Answer:
Substitute in the values of both given coordinates & form 2 equations:
[tex]\left \{ {{A(2)+B(-1)=1} \atop {A(-3)+B(-2)=1}} \right. \\\\=\left \{ {{2A-B=1} \atop {-3A-2B=1}} \right.[/tex]
Find the value of B from the equation 2A - B = 1:
[tex]2A-B=1\\-B=1-2A\\B=2A-1[/tex]
Substitute in the B-value to the other equation:
[tex]-3A-2B=1\\-3A-2(2A-1)=1\\-3A-4A+2=1\\-7A=1-2\\-7A=-1\\A=\frac{-1}{-7} =\frac{1}{7}[/tex]
Find the B-value using the equation from before:
[tex]B=2A-1=2(\frac{1}{7})-1=\frac{2}{7} -\frac{7}{7} =-\frac{5}{7}[/tex]
Therefore the equation Ax + By = 1 would equal:
[tex]\frac{1}{7} x-\frac{5}{7} y=1[/tex]
how many models does the following set have? 5,5,5,7,8,12,12,12,150,150,150
The three modes are 5, 12, and 150 since they occur the most times and they tie one another in being the most frequent (each occurring 3 times).
Only the 7 and 8 occur once each, and aren't modes. Everything else is a mode. It's possible to have more than one mode and often we represent this as a set. So we'd say the mode is {5, 12, 150} where the order doesn't matter.
Suppose you are conducting a study to determine if women are better drivers than men. You send your survey to over 1000 students on your campus and 5 students respond that women are better drivers and 4 students respond that women are not better drivers. What is the sample proportion for women as the better drivers using the large-sample method?
Answer:
555.56
Step-by-step explanation:
Purpose of the study: To determine if women are better drivers than men.
Survey or Opinion population: 1,000
You are experimenting on 9 out of a thousand opinions.
5 of these opinions are that women are better drivers
4 of these opinions are that women are not better drivers
You want to know the sample (full sample size is 9) proportion for women as better drivers; using the large sample method. This method is also called the asymptotic method.
This involves approximating the desired statistic, with just a small fraction of the population; in this case, 9/1000.
This approximation will get more and more accurate as sample size increases and you know that a larger sample size gives a better representation and interpretation of the population preference!
So using ratio, the sample proportion for women as the better drivers is given by:
5/9 x 1000 = 555.56 opinions
Find the product :
1) 6/10 × 10/6 × 5/9
2) 6/10 × 4/3 × 10/20
Hello!
1) 6/10 × 10/6 × 5/9 = 1/10 × 10 × 5/9 = 1 × 5/9 = 5/9 or 0,5
2) 6/10 × 4/3 × 10/20 = 6 × 4/3 × 1/20 = 2 × 4 × 1/20 = 2 × 1/5 = 2/5 or 0,4
Good luck! :)
Answer:
1) 5/9
2) 2/5
Explanation:
1) 6/10 × 10/6 × 5/9=
Multiply all the denominators and all the numerators then simplify= 300/540 = 5/9
2) 6/10 × 4/3 × 10/20=
Multiply all the denominators and all the numerators then simplify= 240/600 = 2/5
If a + b = s and a - b = t, then which of the following expresses the value of ab in terms of s and t?
Please help me out
Answer:
=(s^2 - t^2)/4
Step-by-step explanation:
a + b = s and a - b = t,
Add the two equations together
a + b = s
a - b = t
----------------
2a = s+t
a = (s+t)/2
Subtract the two equations
a + b = s
- a + b = -t
-------------------
2b =(s-t)
b = (s-t)/2
We want to find ab
ab = (s+t)/2 * (s-t)/2
FOIL
=(s^2 - t^2)/4
which choice are equivalent to the expression below? Check all that apply
I could not get the expressions to type correctly because I am new so I am sending a picture. I am having trouble working backwards to figure out which once to choose.
Answer:
A, B, and E apply
Step-by-step explanation:
One thing we can do is to make everything in the same format, under one square root, with no non-square roots.
First, we can say that 6 is equal to √36 as 6² =36, and 6 ≥ 0. Therefore, 6√3 = √36 * √3 = √108
For A, √3 * √36 = √108, so this applies
For B, √18 * √6 = √108, so this applies
For C, 108² = √something bigger than 108 = √11664, so this does not apply
For D, √54 ≠ √108, so this does not apply
For E, √108 = √108, so this applies
For F, √3 * √6 = √18, so this does not apply
What are the zeros of f(x) = (x - 2)(x + 7)? Select all that apply.
A. X= -7
B. X = -2
C. X = 2
D. X = 7
Answer:
2 = x -7 = x
Step-by-step explanation:
f(x) = (x - 2)(x + 7)
y = (x - 2)(x + 7)
Set y = 0
0 = (x - 2)(x + 7)
Using the zero product property
0 = x-2 0 = x+7
2 = x -7 = x
Answer:
Zeros happen when f(x) = 0. There are two zeros in the given function:
when (x - 2) = 0when (x + 7) = 0Therefore solve both equations above and you'll get:
Zero #1 = 2Zero #2 = -7th of
cm.
4 Mrs. Ayer is painting the outside of her son's toy
box, including the top and bottom. The toy box
measures 3 feet long, 1.5 feet wi de, and 2 feet high.
What is the total surface area she will paint?
1) 9.0 ft
2) 13.5 ft?
3) 22.5 ft?
4) 27.0 ft
Chau Took 5 3/8 hours to clean the bedroom. Then he took a 1/2 to clean the den. How much total time did he take to clean two rooms.
Answer:
It took Chau 5 hours, 52 minutes, and 30 seconds to clean both rooms.
Step-by-step explanation:
Given that Chau took 5 3/8 hours to clean the bedroom, and then he took a 1/2 to clean the den, to determine how much total time did he take to clean two rooms the following calculation must be performed:
5 + 3/8 + 1/2 = X
5 + 0.375 + 0.5 = X
5.875 = X
0.875 = 7/8
60/8 x 7 = 52.5
Therefore, it took Chau 5 hours, 52 minutes, and 30 seconds to clean both rooms.
Which of the following best describes the expression 4(y + 6)?
The product of a constant factor of four and a factor with the sum of two terms
The sum of a constant factor of six and a factor with the product of two terms
The product of two constant factors four and six plus a variable
The sum of two constant factors four and six plus a variable
Answer:
The product of a constant factor of four and a factor with the sum of two terms
Step-by-step explanation:
4(y + 6)
This is two terms, a constant 4 and a term with y+6
We a multiplying so we have a product
Answer:
A
Step-by-step explanation:
I believe A is the best answer because 4 is the constant factor with the sum of y + 6. I just think it best rrepresents the equation! :)
What procedure might one use to solve percent problems using proportions ?
Answer:
Proportions and percent
A five-year prospective cohort study has just been completed. The study was designed to assess the association between supplemental vitamin A exposure and mortality and morbidity for measles. The relative risk for incidence of measles was 0.75 and the relative risk for measles mortality was 0.5. Regarding the relative risk, which statement is correct?
a. Exposure to vitamin A appears to protect against morbidity and mortality for measles.
b. Exposure to vitamin A appears to be a risk factor for morbidity and mortality for measles.
c. Exposure to vitamin A is not associated with morbidity and mortality for measles.
d. Exposure to vitamin A is a risk factor for morbidity and a protective factor for mortality for measles.
Answer:
Assessing the association between supplemental vitamin A exposure and mortality and morbidity for measles:
Regarding the relative risk, the correct statement is:
a. Exposure to vitamin A appears to protect against morbidity and mortality for measles.
Step-by-step explanation:
Relative risk for incidence of measles = 0.75
Relative risk for measles mortality = 0.5
Relative risk for mortality and morbidity for measles = 0.375 (0.75 * 0.5)
The combined relative risk is less than 50%
The association is weak because RR is less than 1.
Therefore, there is no association between supplemental vitamin A exposure and mortality and morbidity for measles.
Last year Diana sold 800 necklaces. This year she sold 1080 necklaces. what is the percentage increase of necklaces she sold?
Answer:
the percentage increase is 35%
Help! Given that tanθ=-1, what is the value of secθ, for 3π/2<θ<2π?
Answer: Choice B) [tex]\sqrt{2}[/tex]
Work Shown:
[tex]\sec^2(\theta) = \tan^2(\theta) + 1\\\\\sec^2(\theta) = (\tan(\theta))^2 + 1\\\\\sec^2(\theta) = (-1)^2 + 1\\\\\sec^2(\theta) = 2\\\\\sec(\theta) = \sqrt{2}\\\\[/tex]
Note: secant is positive in quadrant Q4, when theta is between 3pi/2 radians and 2pi radians (270 degrees and 360 degrees). So that's why we don't consider the minus form of the plus minus.
answers please formula
Answer:
-5
2
-125
-3
Step-by-step explanation:
5 + A = 0
Subtract 5 from both sides.
A = -5
-8/4 - B = -4
-2 - B = -4
B + 2 = 4
B = 2
C ÷ 25 = -5
C = -125
D × 13 = -39
D × 13/13 = -39/13
D = -3
BRAINLIESTT A spinner is divided into 8 equal-sized sections, and each section is labeled with a number 1 through 8.
if Kathryn spins the arrow on the spinner twice, what is the probability that the arrow will land on a section with an odd number the first time
and a number greater than 6 on the second spln?
Answer:
The probability would be 1/8.
Step-by-step explanation:
The probability of the spinner landing on an odd number is 1/2, and the probability of the spinner landing on a number greater than 8 is 1/4. So we multiply those two probabilites to get our answer 1/8.
(15 Points) Indicate the general rule for the arithmetic sequence with a3 = -4 and a8 = -29.
Step-by-step explanation:
[tex]a_3 [/tex] = - 4
[tex]a_3 [/tex] = a* + (3- 1) d*
- 4 = a + 2d . . . . . . . . .(i)
[tex]a_8 [/tex] = - 29
[tex]a_8 [/tex] = a + ( 8 - 1) d
- 29 = a + 7d . . . . . . . . (ii)
subtracting equations (i) and (ii)
25 = 5d
d = -5
placing d = -5 in equation (i)
a - 10 = -4
a = 6
For an arithmetic Progtession
[tex]a_n [/tex] = a + (n - 1)d
[tex]a_n [/tex] = 6 + (n- 1)-5
[tex]a_n [/tex] = 6 - 5n + 5
[tex] \underline {a_n = 11 - 5n }[/tex]
[tex]\\[/tex]
*[tex] \boxed{ \mathfrak { a \:stands\: for\: first\: term } } [/tex]
*[tex] \boxed{ \mathfrak { d \:stands\: for\: common \: difference } } [/tex]
Answer:
General rule » -5n+11
Step-by-step explanation:
a3 = a+2d = -4 .......(1)
a8=a+7d = -29..........(2)
(2)-(1) » 5d= -25
d = -25/5
. = -5
substitute d = -5 in ( 1)
» a-2×-5= -4
a-10 = -4
a = -4 +10
= 6
General rule » a +(n-1)d
» 6 +(n-1)×-5
» 6-5n+5
» -5n+11
Create a sample of 10 numbers that has a mean of 8.6.
Answer:
10 + 8 + 10 + 10 + 10 + 10 + 8 + 8 + 6 + 6
Many universities and colleges have instituted supplemental instruction (SI) programs, in which a student facilitator meets regularly with a small group of students enrolled in the course to promote discussion of course material and enhance subject mastery. Suppose that students in a large statistics course (what else?) are randomly divided into a control group that will not participate in SI and a treatment group that will participate. At the end of the term, each student’s total score in the course is determined.
a. Are the scores from the SI group a sample from an existing population? If so, what is it? If not, what is the relevant conceptual population?
b. What do you think is the advantage of randomly dividing the students into the two groups rather than letting each student choose which group to join?
c. Why didn’t the investigators put all students in the treatment group? Note: The article "Supplemental Instruction: An Effective Component of Student Affairs Programming" (J. of College Student Devel., 1997: 577–586) discusses the analysis of data from several SI programs.
Answer:
Step-by-step explanation:
Let many universities and colleges have conducted supplemental instruction(SI) programs. In that a student facilitator he meets the students group regularly who are enrolled in the course to promote discussion of course material and enhance subject mastery.
Here the students in a large statistics group are classified into two groups:
1). Control group: This group will not participate in SI and
2). Treatment group: This group will participate in SI.
a)Suppose they are samples from an existing population, Then it would be the population of students who are taking the course in question and who had supplemental instruction. And this would be same as the sample. Here we can guess that this is a conceptual population - The students who might take the class and get SI.
b)Some students might be more motivated, and they might spend the extra time in the SI sessions and do better. Here they have done better anyway because of their motivation. There is other possibility that some students have weak background and know it and take the exam, But still do not do as well as the others. Here we cannot separate out the effect of the SI from a lot of possibilities if you allow students to choose.
The random assignment guarantees ‘Unbiased’ results - good students and bad are just as likely to get the SI or control.
c)There wouldn't be any basis for comparison otherwise.
(07.05A)
Which statement best explains whether y = 4x + 8 is a linear function or a nonlinear function?
Answer:
Step-by-step explanation:
There are no statements provided, but since it is modeled after the linear function y = mx + b, it is a line. m is the slope or rate of change (which is constant; that's what makes this a line!), and b is the y-intercept (the value of y when x is equal to 0). Its slope is 4 (the function raises 4 units for every 1 unit it moves to the right). Its y-intercept is 8, having the coordinate (0, 8).
Answer:
y = 4x + 8 is a linear function.
Step-by-step explanation:
No statements are given, but here's why:
- It's in slope-intercept form, y = mx + b.
- It has a constant slope.
- A non-linear function does not have a constant slope, and this one does.
x^{2}-7x-25=0 to the nearest tenth
Answer:
x = 9.6
x = - 2.6
Step-by-step explanation:
[tex]x=\frac{-b±\sqrt{b^{2}-4ac } }{2a}[/tex]
Ignore the before the ± it wouldn't let me type it correctly.
x² - 7x - 25 = 0
a = 1
b = - 7
c = - 25
[tex]x=\frac{-(-7)±\sqrt{-7^{2}-4((1)(-25)) } }{2(1)}[/tex]
[tex]x=\frac{7±\sqrt{49-4((1)(-25)) } }{2(1)}[/tex]
[tex]x=\frac{7±\sqrt{49+100 } }{2(1)}[/tex]
[tex]x=\frac{7±\sqrt{149 } }{2}[/tex]
[tex]x=\frac{7±12.2}{2}[/tex]
Two separate equations
[tex]x=\frac{7+12.2}{2}[/tex]
[tex]x=\frac{7-12.2}{2}[/tex]
[tex]x=\frac{7+12.2}{2}[/tex]
[tex]x=\frac{19.2}{2}[/tex]
x = 9.6
[tex]x=\frac{7-12.2}{2}[/tex]
[tex]x=\frac{-5.2}{2}[/tex]
x = - 2.6
For this just use the quadratic formula to find the zeros. In this case, you get 7 +/- square root 149 over 2. Which gives you -2.6 and 9.6.
I need help with this
Answer:
below
Step-by-step explanation:
A AND C is the right option
congruent angles are angles with exactly the same measure
solve the equation
r²-4s+s²=8r+2s=28
Answer:
[tex] {r}^{2} - 4s + {s}^{2} = 8r + 2s = 28 \\ \\ r = \frac{24}{5 } - i \frac{ \sqrt[4]{129} }{5} \\ \: s = \frac{58}{5} + i \frac{ \sqrt[2]{129} }{5 } \\ \\ r = \frac{24}{5} + i \frac{ \sqrt[4]{129} }{5} \\ s = \frac{58}{5} - i \frac{ \sqrt[2]{129} }{5} [/tex]
Please help
4. The equation of a curve is y = (3 - 2x)^3 + 24x.
(a) Find an expression for dy/dx
5. The equation of a curve is y = 54x - (2x - 7)^3.
(a) Find dy/dx
(4) y = (3 - 2x)³ + 24x
Use the power and chain rules:
dy/dx = 3 (3 - 2x)² d/dx [3 - 2x] + 24
dy/dx = 3 (3 - 2x)² (-2) + 24
dy/dx = -24x ² + 72x - 30
(5) y = 54x - (2x - 7)³
Same basic procedure:
dy/dx = 54 - 3 (2x - 7)² d/dx [2x - 7]
dy/dx = 54 - 3 (2x - 7)² (2)
dy/dx = -24x ² + 168x - 240
1+4=5
2+3=10
10+5=25
4+1?
Answer:
8
Step-by-step explanation:
Find the midpoint of the line segment with end coordinates of: (-2,-2) and (2,8)
Answer:
(0 ; 3)
Step-by-step explanation:
hello :
the midpoint of the line segment is : ((-2+2)/2 ;(-2+8)/2 )
(0 ; 3)
A study conducted by the Center for Population Economics at the University of Chicago studied the birth weights of 614 babies born in New York. The mean weight was 3398 grams with a standard deviation of 892 grams. Assume that birth weight data are approximately bell-shaped. Estimate the number of newborns who weighed between 1614 grams and 5182 grams. Round to the nearest whole number.
Answer:
The number of newborns who weighed between 1614 grams and 5182 grams was of 586.
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 mean weight was 3398 grams with a standard deviation of 892 grams.
This means that [tex]\mu = 3398, \sigma = 892[/tex]
Proportion that weighed between 1614 and 5182 grams:
p-value of Z when X = 5182 subtracted by the p-value of Z when X = 1614.
X = 5182
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{5182 - 3398}{892}[/tex]
[tex]Z = 2[/tex]
[tex]Z = 2[/tex] has a p-value of 0.9772
X = 1614
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{1614 - 3398}{892}[/tex]
[tex]Z = -2[/tex]
[tex]Z = -2[/tex] has a p-value of 0.0228
0.9772 - 0.0228 = 0.9544.
Out of 614 babies:
0.9544*614 = 586
The number of newborns who weighed between 1614 grams and 5182 grams was of 586.
What is the chance of getting 3 of the same cards in a row in a 52 cards deck?
Answer:
1/425
Step-by-step explanation:
The first card can be any card, so we don’t have to evaluate the probability.
Now we can suppose that the exit card is a two
- For the second card we have 3/51 of possibilities that is a 2 = 1/17
- For the third card we have 2/50 of possibilities that is a 2 = 1/25
1/17 * 1/25 = 1/425
To test the effectiveness of a business school preparation course, 8 students took a general business test before and after the course. The results are given below. Exam Score Exam Score Student Before Course (1) After Course (2) 1 530 670 2 690 770 3 910 1,000 4 700 710 5 450 550 6 820 870 7 820 770 8 630 610 If they hope that the prep course is effective in improving the exam scores, what is the alternative hypothesis?
Solution :
Group Before After
Mean 693.75 743.75
Sd 155.37 143.92
SEM 54.93 50.88
n 8 8
Null hypothesis : The preparation course not effective.
[tex]$H_0: \mu_d = 0$[/tex]
Alternative hypothesis : The preparation course is effective in improving the exam scores.
[tex]$H_a : \mu_d>0$[/tex] (after - before)
help please! i'm in class and i have 10 mins left. :)
Answer:
3:8
Step-by-step explanation:
i will gadit
that only
A cylindrical piece of iron pipe is shown below. The wall of the pipe is 1.25 inches thick: The figure shows a cylinder of height 14 inches and diameter 8 inches What is the approximate inside volume of the pipe?
332 cubic inches
69 cubic inches
703 cubic inches
99 cubic inches
Answer: 332 cubic inches
Step-by-step explanation:
You can eliminate 69 and 99 as those answers don't make any sense. This leaves you with 703 and 332.
It says the wall of the pipe is 1.25 inches thick so you multiply that by 2 and subtract it by the diameter to get the insider diameter of 5.5
Now you just use the equation V = (3.14)(r^2)(14) where the radius is half of 5.5.
So to finalize the equation you get V = (3.14)(5.5)^2(14) which comes out to 332 cubic inches
The best choice is 332 cubic inches.
69 cubic inches and 99 cubic inches are less and 703 cubic inches is a large approximation.
Diameter = d= 8 inches
Height= Length = l= 14 inches
Thickness= 1.25 inches
Outer Radius= R= diameter/2= 8/2=4 inches
Inner radius = r= Radius - thickness
= 4- 1.25= 2.75 inches
Volume of the cylinder = Area × length
= π r²× l
= 22/7 × (2.75)² × 14
= 332. 616 inches cube
So the best answer is 332 cubic inches
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