The answer is the population grew over the hundred-year span by [tex]6.481*(10)^6[/tex]
Given that in 2014, the population of people in Ohio = [tex]11.59[/tex] million
Also given that One-hundred years earlier of the year 1914, the population = [tex]5.109[/tex] million people
One-hundred years earlier in the year 2014 = 2014 [tex]- 100[/tex] years
One-hundred years earlier in the year 2014 = Year 1914
The scientific notation of the year 2014 population is [tex]11.59*(10)^6[/tex]
The scientific notation of the year 1914 population is [tex]5.109*(10)^6[/tex]
How much did the population grow over the hundred-year span?
Growth of the population from 1914-2014 = [tex]11.59*(10)^6 - 5.109*(10)^6[/tex]
Growth of the population from 1914-2014 = [tex]6.481*(10)^6[/tex]
Conclusion: The population grew over the hundred-year span by [tex]6.481*(10)^6[/tex]
Learn more about scientific notation here https://brainly.com/question/1705769
A social media platform states that a social media post from a marketing agency has 7 hashtags, on average. A digital marketing specialist studying social media advertising believes the average number of hashtags used in a post from a marketing agency is different than the number stated by the social media platform. After completing a study, the digital marketing specialist found that the average number of hashtags used by a marketing agency in a social media post is 7.9 hashtags on average.
As the digital marketing specialist sets up a hypothesis test to determine if their belief is correct, what is their claim?
a. The average number of hashtags used in a social media post from a marketing agency is different than 7 hashtags.
b. The average number of hashtags used in a social media post from a marketing agency is different than 7.9 hashtags.
c. Marketing agencies use too many hashtags in a social media post.
d. The average number of hashtags used in a social media post from a marketing agency is 7 hashtags.
Answer:
a. The average number of hashtags used in a social media post from a marketing agency is different than 7 hashtags.
Step-by-step explanation:
A social media platform states that a social media post from a marketing agency has 7 hashtags, on average.
This means that at the null hypothesis, we test if the mean is 7, that is:
[tex]H_0: \mu = 7[/tex]
A digital marketing specialist studying social media advertising believes the average number of hashtags used in a post from a marketing agency is different than the number stated by the social media platform.
Keyword is different, so at the null hypothesis, we test if the mean is different of 7, that is:
[tex]H_1: \mu \neq 7[/tex]
Thus, the correct answer is given by option a.
Help please anyone???
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Answer:
x^2/1 +y^2/81 = 1
Step-by-step explanation:
We know that the equation of a unit circle is ...
x^2 +y^2 = 1 . . . . . equation of a unit circle
We also know that replacing x with x/a in a function will expand the graph by a factor of 'a'. Similarly, replacing y with y/b will do the same in the vertical direction.
An ellipse is a circle that has had different expansion factors applied along its different axes. Here, the given points tell us the center of the ellipse is (0, 0), and that it has been expanded by a factor of 9 in the y-direction and a factor of 1 in the x-direction This means the equation for it would be ...
(x/1)^2 +(y/9)^2 = 1 . . . . . equation for desired ellipse
In the required form, this is ...
[tex]\dfrac{x^2}{1}+\dfrac{y^2}{81}=1[/tex]
(A) A small business ships homemade candies to anywhere in the world. Suppose a random sample of 16 orders is selected and each is weighed. The sample mean was found to be 410 grams and the sample standard deviation was 40 grams. Find the 90% confidence interval for the mean weight of shipped homemade candies. (Round your final answers to the nearest hundredth)
(B) When 500 college students are randomly selected and surveyed; it is found that 155 own a car. Find a 90% confidence interval for the true proportion of all college students who own a car.
(Round your final answers to the nearest hundredth)
(C) Interpret the results (the interval) you got in (A) and (B)
The correct answer to the given question is "[tex]\bold{392.47\ < \mu <\ 427.53}[/tex],[tex]\bold{0.28 \ < P <\ 0.34}[/tex], and for Interpret results go to the C part.
Following are the solution to the given parts:
A)
[tex]\to \bold{(n) = 16}[/tex]
[tex]\to \bold{(\bar{X}) = 410}[/tex]
[tex]\to \bold{(\sigma) = 40}[/tex]
In the given question, we calculate [tex]90\%[/tex] of the confidence interval for the mean weight of shipped homemade candies that can be calculated as follows:
[tex]\to \bold{\bar{X} \pm t_{\frac{\alpha}{2}} \times \frac{S}{\sqrt{n}}}[/tex]
[tex]\to \bold{C.I= 0.90}\\\\\to \bold{(\alpha) = 1 - 0.90 = 0.10}\\\\ \to \bold{\frac{\alpha}{2} = \frac{0.10}{2} = 0.05}\\\\ \to \bold{(df) = n-1 = 16-1 = 15}\\\\[/tex]
Using the t table we calculate [tex]t_{ \frac{\alpha}{2}} = 1.753[/tex] When [tex]90\%[/tex] of the confidence interval:
[tex]\to \bold{410 \pm 1.753 \times \frac{40}{\sqrt{16}}}\\\\ \to \bold{410 \pm 17.53\\\\ \to392.47 < \mu < 427.53}[/tex]
So [tex]90\%[/tex] confidence interval for the mean weight of shipped homemade candies is between [tex]392.47\ \ and\ \ 427.53[/tex].
B)
[tex]\to \bold{(n) = 500}[/tex]
[tex]\to \bold{(X) = 155}[/tex]
[tex]\to \bold{(p') = \frac{X}{n} = \frac{155}{500} = 0.31}[/tex]
Here we need to calculate [tex]90\%[/tex] confidence interval for the true proportion of all college students who own a car which can be calculated as
[tex]\to \bold{p' \pm Z_{\frac{\alpha}{2}} \times \sqrt{\frac{p'(1-p')}{n}}}[/tex]
[tex]\to \bold{C.I= 0.90}[/tex]
[tex]\to\bold{ (\alpha) = 0.10}[/tex]
[tex]\to\bold{ \frac{\alpha}{2} = 0.05}[/tex]
Using the Z-table we found [tex]\bold{Z_{\frac{\alpha}{2}} = 1.645}[/tex]
therefore [tex]90\%[/tex] the confidence interval for the genuine proportion of college students who possess a car is
[tex]\to \bold{0.31 \pm 1.645\times \sqrt{\frac{0.31\times (1-0.31)}{500}}}\\\\ \to \bold{0.31 \pm 0.034}\\\\ \to \bold{0.276 < p < 0.344}[/tex]
So [tex]90\%[/tex] the confidence interval for the genuine proportion of college students who possess a car is between [tex]0.28 \ and\ 0.34.[/tex]
C)
In question A, We are [tex]90\%[/tex] certain that the weight of supplied homemade candies is between 392.47 grams and 427.53 grams.In question B, We are [tex]90\%[/tex] positive that the true percentage of college students who possess a car is between 0.28 and 0.34.Learn more about confidence intervals:
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PLEASE HELP ASAP, Thank you
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Answer:
2.244
Step-by-step explanation:
Your answer looks like it may have a transcription error.
The period is reasonably computed as the difference of the x-values of the given points:
period = 4.114 -1.870 = 2.244 . . . seconds
Which is the graph of the linear inequality 2x – 3y < 12? On a coordinate plane, a solid straight line has a positive slope and goes through (0, negative 4) and (3, negative 2). Everything to the right of the line is shaded. On a coordinate plane, a dashed straight line has a positive slope and goes through (0, negative 4) and (3, negative 2). Everything to the right of the line is shaded. On a coordinate plane, a dashed straight line has a positive slope and goes through (0, negative 4) and (3, negative 2). Everything to the left of the line is shaded.
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Answer:
(c) On a coordinate plane, a dashed straight line has a positive slope and goes through (0, negative 4) and (3, negative 2). Everything to the left of the line is shaded.
Step-by-step explanation:
The x-coefficient is positive, so we can determine the shading from ...
2x ... < ... (pay attention to the x-term and the inequality symbol)
That is, the solution region will have x values that are less than those on the (dashed) boundary line. Lower x-values are to the left, hence shading is on the left side of the boundary. (That's all you need to know here to make the correct choice.)
_____
Additional comment
If the choices are "above" or "below", then you will want to look at the y-term and the inequality symbol. If the coefficient of the variable of interest is negated (as it is for y here), then you need to consider the inequality symbol reversed: -y < ... ⇔ y > .... Here, that means the shading is above the line. Since the slope of the line is positive, "left" and "above" are the same thing.
Answer:
c
Step-by-step explanation:
E2021
180 °
X °
26 °
X = ? °
Answer:
X = 64
Step-by-step explanation:
All of the angles are right angles (because of the square at one of the angles shown above). This means each angle equals 90 degrees. If X + 26 = 90, then X = 64 because 90 - 26 = 64. I hope this helps!
Answer: X = 64
Step-by-step explanation:
The area of a rectangle is 44 m^2, and the length of the rectangle is 3 m less than twice the width. Find the dimensions of the rectangle.
length :
width :
Answer:
Length:8
Width:5.5
Step-by-step explanation:
We're given area = 44m^2, and the formula for the area of a rectangle is the length multiplied by the width. So,
A = L * w = 44
We're given that the length is 3m shorter than 2 times the width, which is 2w - 3. "2w" is the same as "2 times the width", and the 3 is subtracted because it says 3m shorter than 2 times the width. So L = 2w - 3, and we can substitute that into our equation above.
(2w - 3)(w) = 44
2w^2 - 3w - 44 = 0
Use the quadratic formula here.
x = {3 ± √(-3)^2 - 4(-44)(2)}/2(2)
= {3 ± √9 + 352}/4
= (3 ± 19)/4
You'll get two answers, but remember, we're measuring the length of the sides of shapes, so it has to be positive. It's impossible to have negative lengths, so we're going to stick with the (3 + 19)/4 answer, which is 22/4, which is 5.5. However, we are not finished yet. This is just the width. Now we need to plug it into the equation for length, which was 2w - 3
2(5.5) - 3 = 11 - 3 = 8
The length is 8m and the width is 5.5m.
A group of high school students were surveyed about their handedness and their favorite sport. The results are displayed below.
Which of the following statements is not true, according to the graph?
The left-handed group has a higher percentage of people who prefer baseball.
The right-handed group has a lower percentage of people who prefer basketball.
The percentage of people who prefer soccer has a lower percentage in the left-handed group.
The percentage of people who prefer football is approximately the same for the right- and left-handed groups.
Answer:
The percentage of people who prefer football is approximately the same for the right- and left-handed groups.
Step-by-step explanation:
The bar for the right-handed group representing soccer is between 10% and 20% (below 20%) while the bar for the left-handed group representing soccer is at 20%.
Percentage of left-handed group of people who prefer soccer is higher than the right-handed group who prefer soccer. Therefore, they don't have the same percentage.
Answer:
D
Step-by-step explanation:
;)
What is the value of 3x^2 + 4y^2 if x = 2 y = 1
Answer:
16 is answer
Step-by-step explanation:
3(2)^2+4(1)^2= 3(4)+4(1)=12+4=16
A car travels 12 km in 15 minutes.
Work out the average speed of the car in km/h.
Step-by-step explanation:
s=12km t=15m
15m--> km= 15/60= 0,25h
V=s/t
V=12km/0,25h
V= 48 km/h
Find the equation of the line passing through the point (-7,2)(−7,2) that is perpendicular to the line 4x - 3y = 104x−3y=10.
Answer:
Step-by-step explanation:
Slope of the given line: m=4/3
Slope of the perpendiclar : m'=-3/4 (the inverse of the opposed of m)
Equation of the perpendiclar line: (passing through (-7,2))
[tex]y-2=(x+7)*\dfrac{-3}{4} \ or\\\\ y=-\dfrac{3x}{4} -\dfrac{13}{4}[/tex]
The five number summary of a dataset is given as
0, 4, 12, 14, 20
An observation is considered an outlier if it is below _______
An observation is considered an outlier if it is above _______
The five number summary of a dataset is given as
2, 8, 14, 18, 20
An observation is considered an outlier if it is below _______
An observation is considered an outlier if it is above _______
.
.
Given:
The five number summary of two data sets are given as:
a) 0, 4, 12, 14, 20
b) 2, 8, 14, 18, 20
To find:
The range for the outliers.
Solution:
We know that,
An observation is considered an outlier if it is below [tex]Q_1-1.5(IQR)[/tex]
An observation is considered an outlier if it is above [tex]Q_3+1.5(IQR)[/tex]
Where, IQR is the interquartile range and [tex]IQR=Q_3-Q_1[/tex].
The five number summary of two data sets are given as:
0, 4, 12, 14, 20
Here, [tex]Q_1=4[/tex] and [tex]Q_3=14[/tex].
Now,
[tex]IQR=14-4[/tex]
[tex]IQR=10[/tex]
The range for the outliers is:
[tex][Q_1-1.5(IQR),Q_3+1.5(IQR)]=[4-1.5(10),14+1.5(10)][/tex]
[tex][Q_1-1.5(IQR),Q_3+1.5(IQR)]=[4-15,14+15][/tex]
[tex][Q_1-1.5(IQR),Q_3+1.5(IQR)]=[-11,29][/tex]
An observation is considered an outlier if it is below -11.
An observation is considered an outlier if it is above 29.
The five number summary of two data sets are given as:
2, 8, 14, 18, 20
Here, [tex]Q_1=8[/tex] and [tex]Q_3=18[/tex].
Now,
[tex]IQR=18-8[/tex]
[tex]IQR=10[/tex]
The range for the outliers is:
[tex][Q_1-1.5(IQR),Q_3+1.5(IQR)]=[8-1.5(10),18+1.5(10)][/tex]
[tex][Q_1-1.5(IQR),Q_3+1.5(IQR)]=[8-15,18+15][/tex]
[tex][Q_1-1.5(IQR),Q_3+1.5(IQR)]=[-7,33][/tex]
An observation is considered an outlier if it is below -7.
An observation is considered an outlier if it is above 33.
If f(x) = 3x-1 and g(x)= x+2 find (f-g) (x)
Answer:
2x-3
Step-by-step explanation:
f(x) = 3x-1
g(x)= x+2
(f-g) (x) = 3x-1 - (x+2)
Distribute the minus sign
= 3x-1 -x-2
Combine like terms
= 3x-x -1-2
=2x -3
If the cube root parent function is horizontally stretched by a factor of 4, then translated 5 units right and 3 units up, write an equation to represent the new function?
Answer:
The cube root parent function:
f(x) = [tex]\sqrt[3]{x}[/tex]Horizontally stretched by a factor of 4:
g(x) → f(1/4x) = [tex]\sqrt[3]{1/4x}[/tex]Translated 5 units right:
h(x) → g(x - 5) = [tex]\sqrt[3]{1/4x - 5}[/tex]Translated 3 units up:
k(x) → h(x) + 3 = [tex]\sqrt[3]{1/4x - 5} + 3[/tex]Each marble bag sold by Debra's Marble Company contains 8 yellow marbles for every 4 blue marbles. If a bag has 56 yellow marbles, how many blue marbles does it contain?
Answer:
28 blue marbles
Step-by-step explanation:
yellow: blue
8 4
To get to 56 yellow marbles multiply by 7
yellow: blue
8*7 4*7
56 28
There will be 28 blue marbles
which expression is equivalent to c^2 - 4 / c + 3 /
Step-by-step explanation:
[tex] \frac{ {c}^{2} - 4 }{c + 3} [/tex]
[tex] \frac{(c - 2)(c + 2)}{(c + 3)} [/tex]
help fast I'm dum
and I'm sorry if I keep spamming this.
Curtis types 48 words in 1 minute how many words does Curtis type in 8 minutes? use the following equivalent rates to help solve the problem. how many words does Curtis type in 8 minutes?
Answer:
384
Step-by-step explanation:
Answer:
384 words
Step-by-step explanation:
Number of words typed in 1 minute = 48
So, number of words typed in 8 minutes
= Number of words typed in 1 minute × 8
= 48 × 8
= 384
So, Curtis types 384 words in 8 minutes.
What is the slope of a relation with ordered pairs of (-5, 3) and (4.1).
9/2
2/9
-9/2
-2/9
2
-2
what is 98×63-32×69=
Answer: plz marl brainilist
3966
Step-by-step explanation:
(98 × 63 - 32 × 69
98 * 63) - (32 * 69)
A parallel plate capacitor has an area of 1.5 cm
2
and the plates are separated a distance of 2.0 mm with air between them. How much charge does this capacitor store when connected to a 12V battery?
Step-by-step explanation:
Given:
[tex]A=1.5\:\text{cm}^2×\left(\frac{1\:\text{m}^2}{10^4\:\text{cm}^2}\right)=1.5×10^{-4}\:\text{m}^2[/tex]
[tex]d = 2.0\:\text{mm} = 2.0×10^{-3}\:\text{mm}[/tex]
The charge stored in a capacitor is given by [tex]Q = CV.[/tex] In the case of a parallel-plate capacitor, its capacitance C is given by
[tex]C = \epsilon_0\dfrac{A}{d}[/tex]
where [tex]\epsilon_0[/tex] = permittivity of free space. The amount of charge stored in the capacitor is then
[tex]Q = \left(\epsilon_0\dfrac{A}{d}\right)V[/tex]
[tex]\:\:\:\:\:=\left[\dfrac{(8.85×10^{-12}\:\text{F/m})(1.5×10^{-4}\:\text{m}^2)}{(2.0×10^{-3}\:\text{m})}\right](12\:\text{V})[/tex]
[tex]\:\:\:\:\:=8.0×10^{-12}\:\text{C}[/tex]
A brewery has a beer dispensing machine that dispenses beer into the company's 12 ounce bottles. The distribution for the amount of beer dispensed by the machine follows a normal distribution with a standard deviation of 0.17 ounce. The company can control the mean amount of beer dispensed by the machine. What value of the mean should the company use if it wants to guarantee that 98.5% of the bottles contain at least 12 ounces (the amount on the label)
Answer:
The company should use a mean of 12.37 ounces.
Step-by-step explanation:
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
The distribution for the amount of beer dispensed by the machine follows a normal distribution with a standard deviation of 0.17 ounce.
This means that [tex]\sigma = 0.17[/tex]
The company can control the mean amount of beer dispensed by the machine. What value of the mean should the company use if it wants to guarantee that 98.5% of the bottles contain at least 12 ounces (the amount on the label)?
This is [tex]\mu[/tex], considering that when [tex]X = 12[/tex], Z has a p-value of [tex]1 - 0.985 = 0.015[/tex], so when [tex]X = 12, Z = -2.17[/tex].
Then
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]-2.17 = \frac{12 - \mu}{0.17}[/tex]
[tex]12 - \mu = -2.17*0.17[/tex]
[tex]\mu = 12 + 2.17*0.17[/tex]
[tex]\mu = 12.37[/tex]
The company should use a mean of 12.37 ounces.
Point C partitions AB into two parts so that the ratio of the length of AC to the length of CB is 1:5. What are the coordinates of point ?
Select and drag a number to each empty box to correctly complete the coordinates of point
The coordinates of point C are?
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Answer:
C(-1, -4)
Step-by-step explanation:
We want ...
AC/CB = 1/5
5(C-A) = B-C . . . . multiply by 5CB
6C = B +5A . . . . . add 5A-C
C = (B +5A)/6 . . . divide by 6
C = ((4, 6) +5(-2,-6))/6 = (4-10,6-30)/6 = (-6, -24)/6
C = (-1, -4)
Mark earns $47,800 a year working for a delivery service. He is single and pays $2,152.60 in state income tax each year. He claims no dependents. What is the tax rate of Mark’s state he lives in?
Answer:
4.5%
Step-by-step explanation:
The tax rate=(2152.6/47800)*100=4.5%
Identify the coordinates of the point shown. An image of a coordinate plane with one point plotted. It is 3 units to the left of the y-axis and 6 units below the x-axis. Question 23 options: (−6, 3) (−6, −3) (−3, −6) (3, −6)
Answer:
(-3, -6)
Step-by-step explanation:
always start from the origin! Hope this helps!
11. The coordinates of AABC are A(-1,1), B(3,3),
and C(4, -2). Find the coordinates of points A', B',
and C' under the translations that take
a. P(0,0) to Q(1,3)
b. P(0, -1) to Q(4,-2)
c. P(-1,-2) to Q(-2,2)
Answer:
See explanation
Step-by-step explanation:
Given
[tex]A = (-1,1)[/tex]
[tex]B = (3,3)[/tex]
[tex]C =(4,-2)[/tex]
Solving (a): [tex]P(0,0) \to Q(1,3)[/tex]
This means that:
[tex](x,y) \to (x+1,y+2)[/tex]
So, we have:
[tex]A = (-1,1)[/tex]
[tex]A' = (-1 + 1,1+2)[/tex]
[tex]A' = (0,3)[/tex]
[tex]B = (3,3)[/tex]
[tex]B'= (3 + 1,3+2)[/tex]
[tex]B'= (4,5)[/tex]
[tex]C =(4,-2)[/tex]
[tex]C' = (4+1,-2+1)[/tex]
[tex]C' = (5,-1)[/tex]
Solving (b): [tex]P(0,-1) \to Q(4,-2)[/tex]
This means that:
[tex](x,y) \to (x+4,y-1)[/tex]
So, we have:
[tex]A = (-1,1)[/tex]
[tex]A' = (-1+4,1-1)[/tex]
[tex]A' = (3,0)[/tex]
[tex]B = (3,3)[/tex]
[tex]B'= (3+4,3-1)[/tex]
[tex]B'= (7,2)[/tex]
[tex]C =(4,-2)[/tex]
[tex]C' = (4+4,-2-1)[/tex]
[tex]C' = (8,-3)[/tex]
Solving (c): [tex]P(-1,-2) \to Q(-2,-2)[/tex]
This means that:
[tex](x,y) \to (x-1,y)[/tex]
So, we have:
[tex]A = (-1,1)[/tex]
[tex]A' = (-1-1,1)[/tex]
[tex]A' = (-2,1)[/tex]
[tex]B = (3,3)[/tex]
[tex]B'= (3-1,3)[/tex]
[tex]B'= (2,3)[/tex]
[tex]C =(4,-2)[/tex]
[tex]C'= (4-1,-2)[/tex]
[tex]C'= (3,-2)[/tex]
Eli had mini-golf scores of -3, -4, and -3. What was his total score for the three rounds?
Answer:-10
-3+-4+-3
-3-4=-7
-7+-3=-7-3
=-10
You can often use geometric figures to model objects in the real world. You can transfer your knowledge of the properties of these figures to better understand and describe the objects that they represent. For each shape the table, list three examples of real-world objects that could be modeled by the shape. Use your experiences, the Internet, newspapers, magazines, or other resources to uncover examples.
Geometric figures are basically figures that have a boundary. The geometric figures and their real life examples are:
Rectangular prism: Building block, Gift box, CabinetTriangular prism: Tomblerone, Triangular roofs, Camping tentsCylinder: Pencil holders, Toilet paper rolls, Drink cansCone: Funnel, Party hat, Traffic conePyramid: Pyramids of Egypt, Pyramid roof, Pyramid tentsSphere: Soccer ball, Golf ball, PlanetsTo determine the real life object of each geometric figure, we simply identify objects that have similar features as the geometric figure.
For instance, a rectangular prism has 6 rectangular faces; building blocks, some gift box and cabinets also have 6 rectangular faces.
So, these three real life objects can be used as examples of a rectangular prism.
When the above explanation is applied to the other geometric figures, we come up with the following list:
Triangular prism: Tomblerone, Triangular roofs, Camping tentsCylinder: Pencil holders, Toilet paper rolls, Drink cansCone: Funnel, Party hat, Traffic conePyramid: Pyramids of Egypt, Pyramid roof, Pyramid tentsSphere: Soccer ball, Golf ball, PlanetsRead more about geometric figures at:
https://brainly.com/question/8430622
In the photo are a couple possible answers you could use.
Find formulas for X, Y, and Z in terms of A, B, and C. It may be necessary to make assumptions about the size of a matrix in order to produce a formula.
[A B C 0] [1 0 X Y] = [0 1 Z 0]
Find the formulas for X, Y, and Z. Note that I represents the identity matrix and 0 represents the zero matrix.
Answer:
Here the answer is given as follows,
hola soy nuevo, y quisiera saber como funciona brainly.com, porque yo siempre e utilizado brainly.lat, pero me e cambiado para este.
Answer/Step-by-step explanation:
Hola amigo. Mucho gusto. En Brainly.com puede responder a sus preguntas y obtener explicaciones exhaustivas. Esto le permite aprender de forma más inteligente.
Y... yo hablo pequeno español.
A fisheries biologist has been studying horseshoe crabs. She has sampled 100 horseshoe crabs and recorded their weight (in kilograms) and width (in centimeters). The proposed regression equation is
where the deviations ε i are assumed to be independent and Normally distributed with mean 0 and standard deviation σ . This model was fit to the data using the method of least squares. The following results were obtained from statistical software:
R 2 =0.423, s=2.2018
The quantity s = 2.2018 is an estimate of the standard deviation, σ, of the deviations in the simple linear regression model. The degrees of freedom for s are
a.) 100
b.) 99
c.) 98
d.) 2
Answer:
C. 98
Step-by-step explanation:
The proposed regression equation is weight = b + width * m
R2 = 0.423
A.) What is the regression equation for this example?
The estimate for the y-intercepts is b= 2.3013 and the estimate for the slope is m= 0.7963
In general, we can symbolize the estimated regression equation as ^Y= b + m*Xi. For this example you have to replace it with the calculated values of the regression coefficients to obtain the estimated regression equation:
^Y= 2.3013 + 0.7963Xi
B.) What is the explanatory, or predictor, variable in this study?
The explanatory or predictor variable is the variable that is suspected to have an effect over the response variable. In this example the predictor variable is:
X: Width of a horseshoe crab (cm)
C.) If the researcher wanted to test whether there is a statistically significant relationship between these two variables, what would the test statistic be? Calculate it from the table above.
To test if the regression is significant, the parameter of study will be the slope of the regression equation, symbolically: β. If the slope is equal to zero "β=0" then there is no linear regression between the response and explanatory variable. If the slope is different from zero "β≠0" then the regression is significant and the explanatory variable affects the response variable.
The hypotheses are:
H₀: β=0
H₁: β≠0
α: 0.05
The value of the statistic under the null hypothesis is t= 8.48
D.) What can we say about the p-value?
This test is two-tailed and so is the p-value, remember that the p-value is the probabulity of obtaining a value as extreme as the value of the statistic under the null hypothesis. The distribution for this test is a t with n-2= 100-2= 98 degrees of freedom. You can calculate the p-value as:
P(t₉₈≤-8.48) + P(t₉₈≥8.48)= P(t₉₈ ≤ -8.48) + (1 - P(t₉₈ < 8.48) ≅ 0.00001
E.) Ultimately, the reason that we find test statistics is so that we can compare them to a null distribution. For regression, that is a t-distribution based on the degrees of freedom. With 98 degrees of freedom (100-2), we can safely say that the critical t (or the confidence multiplier) is what?
As mentioned before, this test is two tailed, meaning that the rejection region is divided in two:
Critical values ± = ± = ± 1.984
This means that you'll reject the null hypothesis when the statistic is t ≤ -1.984 or if the statistic is t ≥ 1.984-
F.) Find the confidence interval for the slope.
Using a 95% confidence level, the interval for the slope is:
[m ± Sm]
[0.7963 ± 1.984 * 0.0939]
[0.61; 0.98]
G.) Is there a statistically significant relationship? Answer with the test statistic and the confidence interval.
Yes, there is a significant relationship between the width and weight of the horseshoe crabs.
Using the critical value approach:
The calculated statistic is 8.48 and the critical value is ± 1.984, since the statistic is greater than the positive critical value, the decision is to reject the null hypothesis.
If you pay attention to the confidence interval, which was made at a confidence level complementary to the significance level of the hypothesis test, this interval [0.61; 0.98] doesn't include the "zero". Since the interval doesn't include the value of the parameter stated in the null hypothesis, you can conclude that this hypothesis is not true and therefore reject it.
