Assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. Find the probability that a given score is less than 1.99 and draw a sketch of the region.
Answers
Answer:
Step-by-step explanation:
To find this probability, we shall be using the z-score route
Mathematically ;
z-score = (x -mean)/SD
From the question, x = 1.99, mean = 0 and SD = 1
So z = (1.99-0)/1 = 1.99
So the probability we want to calculate is;
P(z<1.99)
This value can be obtained from the standard normal distribution table.
P(z < 1.99) = 0.9767
The sketch of the region is as shown as in the attachment.
Related Questions
If the bathtub holds a total of 46.2 gallons, how many minutes would it take to fill the entire bathtub? Write an equation in one variable to help you solve the problem. The variable represents the unknown time in minutes.
Answers
Answer:
2.8
Step-by-step explanation:
Hey there!
Well to find the amount of minutes needed to fill a 46.2 gallon bathtub we’ll divide.
46.2 / 16.5
= 2.8
2.58 minutes
Hope this helps :)
Given that the sum of squares for error is 60 and the sum of squares for regression is 140, then the coefficient of determination is:
Answers
Answer:
0.7Step-by-step explanation:
The coefficient of determination which is also known as the R² value is expressed as shown;
[tex]R^{2} = \frac{sum\ of \ squares \ of \ regression}{sum\ of \ squares \ of total}[/tex]
Sum of square of total (SST)= sum of square of error (SSE )+ sum of square of regression (SSR)
Given SSE = 60 and SSR = 140
SST = 60 + 140
SST = 200
Since R² = SSR/SST
R² = 140/200
R² = 0.7
Hence, the coefficient of determination is 0.7. Note that the coefficient of determination always lies between 0 and 1.
The coefficient of determination of the dataset is 0.7
The given parameters are:
[tex]SSE = 60[/tex] --- sum of squared error
[tex]SSR = 140[/tex] --- sum of squared regression
Start by calculating the sum of squared total (SST)
This is calculated using
[tex]SST =SSE + SSR[/tex]
So, we have:
[tex]SST =60 +140[/tex]
[tex]SST =200[/tex]
The coefficient of determination (R^2) is then calculated using
[tex]R^2 = \frac{SSR}{SST}[/tex]
So, we have:
[tex]R^2 = \frac{140}{200}[/tex]
Divide
[tex]R^2 = 0.7[/tex]
Hence, the coefficient of determination is 0.7
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Which polynomial is prime? x2 + 9 x2 – 25 3x2 – 27 2x2 – 8
Answers
This is a sum of squares, which cannot be factored over the real numbers. You'll need to involve complex numbers to be able to factor, though its likely your teacher hasn't covered that topic yet (though I could be mistaken and your teacher has mentioned it).
Choice B can be factored through the difference of squares rule. Therefore, choice B is not prime.
Choice C and D can be factored by pulling out the GCF and then use the difference of squares rule afterward. So we can rule out C and D as well.
Answer:
A
Step-by-step explanation:
because it has a + sign
If all angles are 90 degrees, and the crystal has a square base with a height that is larger than one of the square sides, what type of unit cell is it
Answers
Answer:
Tetragonal unit cell.
Step-by-step explanation:
A unit cell is the smallest part of a material which is formed by a well arranged lattice points. Some common types are; face centered, body center, tetragonal, cubic etc
Tetragonal unit cell has a square top and base, with rectangular sides. The internal angles are [tex]90^{0}[/tex] each, and consists of molecules, atoms, or ions (lattice points) arranged at each corners of the unit cell.
The crystal as described in the given question is a tetragonal unit cell.
Determine whether each equation has one solution, no solution or infinitely many solutions. 4x + 10 = 2(2x + 5) 4x - 5 = 4x + 10 4x - 5 = -5
Answers
Answer:
see below
Step-by-step explanation:
4x + 10 = 2(2x + 5)
Distribute
4x+10 = 4x+10
Since the left side is identical to the right side, there are infinite solutions
4x - 5 = 4x + 10
Subtract 4x from each side
-5 = 10
This is never true, so there are no solutions
4x-5 = -5
Add 5 to each side
4x = 0
x=0
There is one solutions
Which point slope form equations could be produced with the points (3,2) and (4,6)
Answers
Step-by-step explanation:
Equation of a line is y = mx + c
where
m is the slope
c is the y intercept
To find the equation of a line given two points first find the slope of the line and use the formula
y - y1 = m( x - x1) to find the Equation of the line using any of the points given
Slope of the line using points
(3,2) and (4,6) is
[tex]m = \frac{6 - 2}{4 - 3} = \frac{4}{1} = 4[/tex]
So the equation of the line using point
( 3 , 2 ) and slope 4 is
y - 2 = 4( x - 3)Hope this helps you
which rate can you set 7 miles over 1 hour equal to in order to find the distance traveled in 49 hours at 7 miles per hour
Answers
Answer:
Step-by-step explanation:
time = 49 hours
speed = 7 miles/hour
speed = distance / time
∴ distance = speed × time
= 7 × 49
= 343 miles
According to a survey, typical American spends 154.8 minutes per day watching TV. A survey of 50 Internet users results in a mean time watching TV per day of 128.7 minutes, with a standard deviation of 46.5 minutes. Which appropriate test we should use to determine if Internet users spend less time watching TV
Answers
Answer:
Z > ± 1.645
z= 3.968
Step-by-step explanation:
We formulate the null and alternate hypotheses as
H0 =μ2 ≥ μ1 Ha: μ2 <μ1 one sided
Let α= 0.05
Since the sample sizes are large therefore the test statistic used under H0 is
The critical region for α= 0.05 for a one tailed test Z > ± 1.645
Z = (x`2- x`1) /s/ √n
Z= 154.8-128.746.5/√50
z= 26.1/6.577
z= 3.968
Since the calculated value of z lies in the critical region we reject H0 that internet users spend more time or equal time.
A house m by m is surrounded by a walkway m wide. 27 9 1.8 a) Find the area of the region covered by the house and the walkway. b) Find the area of the walkway.
Answers
Answer:
A. 385.56 square meters.
B. 142.56 square meters.
Step-by-step explanation:
A house 27m by 9m is surrounded by a walkway 1.8m wide.
a) Find the area of the region covered by the house and the walkway.
b) Find the area of the walkway.
Let
Length of the house=l=27m
Width of the house=w=9m
Wideness of the walkway=x=1.8m
Area of the region covered by the house and the walkway
=( L + 2*x) * (w + 2*x)
= (27+2*1.8)*(9+2*1.8)
=(27+3.6)*(9+3.6)
=(30.6)*(12.6)
=385.56 square meters.
b) Area of the walkway
= (L + 2*x)*(w + 2*x) - l*w
= (27+2*1.8)*(9+2*1.8) - 27*9
=(27+3.6)*(9+3.6) - 243
=(30.6)*(12.6) - 243
=385.56 - 243
=142.56 square meters.
Musah stands at the centre of a rectangular field. He first takes 50 steps north, then 25 steps
west and finally 50 steps on a bearing of 3150
.
i. Sketch Musah’s movement
ii. How far west is Musah’s final point from the centre?
iii. How far north is Musah’s final point from the centre?
iv. Describe how you would guide a JHS student to find the bearing and distance of
Musah’s final point from the centre.
Answers
Answer:
ii. 75 steps
iii. 75 steps
iv. 106 steps, and [tex]315^{0}[/tex]
Step-by-step explanation:
Let Musah's starting point be A, his waiting point after taking 50 steps northward and 25 steps westward be B, and his stopping point be C.
ii. From the second attachment, Musah's distance due west from A to C (AD) can be determined as;
bearing at B = [tex]315^{0}[/tex], therefore <BCD = [tex]45^{0}[/tex]
To determine distance AB,
[tex]/AB/^{2}[/tex] = [tex]/50/^{2}[/tex] + [tex]/25/^{2}[/tex]
= 25000 + 625
= 3125
AB = [tex]\sqrt{3125}[/tex]
= 55.90
AB ≅ 56 steps
Thus, AC = 50 steps + 56 steps
= 106 steps
From ΔACD,
Sin [tex]45^{0}[/tex] = [tex]\frac{x}{106}[/tex]
⇒ x = 106 × Sin [tex]45^{0}[/tex]
= 74.9533
≅ 75 steps
Musah's distance west from centre to final point is 75 steps
iii. From the secon attachment, Musah's distance north, y, can be determined by;
Cos [tex]45^{0}[/tex] = [tex]\frac{y}{106}[/tex]
⇒ y = 106 × Cos [tex]45^{0}[/tex]
= 74.9533
≅ 75 steps
Musah's distance north from centre to final point is 75 steps.
iv. Musah's distance from centre to final point is AC = AB + BC
= 50 steps + 56 steps
= 106 steps
From ΔACD,
Tan θ = [tex]\frac{75}{75}[/tex]
= 1.0
θ = [tex]Tan^{-1}[/tex] 1.0
= [tex]45^{0}[/tex]
Musah's bearing from centre to final point = [tex]45^{0}[/tex] + [tex]270^{0}[/tex]
= [tex]315^{0}[/tex]
What is the value of the mean from the following set of data: 12,10, 11, 8, 6, 5, 3, 7, 9. Round to the nearest hundredth.
Answers
Answer:
7.88 or 7.9
Step-by-step explanation:
To find the mean, we need to do:
=> (12 + 10 + 11 + 8 + 6 + 5 + 3 + 7 + 9) / 9
=> 71/9
=> 7.88 or 7.9
I divided the sum of all numbers by 9 because we added 9 numbers.
Karl needs a total of $30 to buy a bike. He has $12. He can earn $6 an hour
babysitting. Which equation can be used to find the number of hours, h, Karl has to
babysit to have the money he needs?
30 - 6h + 12 = 0
6+ n = 12
6 + 12 h = 30
6 h + 12 = 30
Answers
Answer:
6h + 12 = 30
Step-by-step explanation:
Hence, the equation obtained for number of hours worked is given as 12 + 6h = 30.
How to write a linear equation?A linear equation for the given case can be written by assuming any variable as the unknown quantity. Then, as per the given data the required operations are done and it is equated to some value.
The total money required is given as $30.
Suppose the number of hours for babysitting be h.
Then, the money earned by doing it is $6h.
And, the total money with Karl is 12 + 6h.
As per the question, the following equations can be written as,
12 + 6h = 30
Hence, the equation for finding the number of hours is given as 12 + 6h = 30.
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Factor 13ab3 + 39a2b5.
Answers
[tex]13ab^3+39a^2b^5\\\\\boxed{\boxed{\boxed{13ab^3(1+3ab^2)}}}\\\\[/tex]
Brazil number one.
Answer:
there's no answer for that equation
The solution system to 3y-2x=-9 and y=-2x+5
Answers
Answer:
[tex]\boxed{(3,-1)}[/tex]
Step-by-step explanation:
Hey there!
Well to find the solution the the given system,
3y - 2x = -9
y = -2x + 5
So to find x lets plug in -2x + 5 for y in 3y - 2x = -9.
3(-2x + 5) - 2x = -9
Distribute
-6x + 15 - 2x = -9
-8x + 15 = -9
-15 to both sides
-8x = -24
Divide -8 to both sides
x = 3
Now that we have x which is 3, we can plug in 3 for x in y = -2x + 5.
y = -2(3) + 5
y = -6 + 5
y = -1
So the solution is (3,-1).
Hope this helps :)
how do you figure out ratios? the problem is 12 quarters to 34 dollars. thanks
Answers
Step-by-step explanation:
When you have a ratio, you put one number as the numerator and than one number as the denominator.
so it would be (12/34)=(x/68)
In this example I made the ratio you are comparing it to have 68 dollars, so when you solve for the amount of quarters you need it should be 24, since all of the numbers in this example are just being doubled.
To solve for x, you multiply 68 on both sides of the equation, 68×(12/34)=x
24=x
So this proves that this is how ratios, are used. It also does not matter what number you place on the numerator or denominator.
[tex]f(x) = sqr root x+3 ; g(x) = 8x - 7[/tex]
Find (f(g(x))
Answers
[tex]f(x)=\sqrt{x+3}\\g(x)=8x-7\\\\f(g(x))=\sqrt{8x-7+3}=\sqrt{8x-4}[/tex]
Please answer this correctly without making mistakes
Answers
Answer:
10 9/20
Step-by-step explanation:
Hey there!
If Hillsboro to Campbell is 16 2/20 and Hillsboro to Oxford is 5 13/20,
we’ll do
16 2/20 - 5 13/20
Imrpoper form
322/20 - 113/20
322 - 113
209/20
10 9/20 miles from Oxford to Campbell.
Hope this helps :)
For an experiment with 3 groups of 10 participants in each group. Fcrit for alpha 0.05=_________
a. 3.35
b. 2.35
c. 5
d. 12
Answers
Answer:
a. 3.35
Step-by-step explanation:
Given that :
an experiment with 3 groups consist of 10 participant in each group.
This implies that:
number of group k = 3
number of participants n = 10
N = nk
N = 10 × 3 = 30
The degree of freedom within can be calculate as:
dfw = N - k
dfw = 30 - 3
dfw = 27
The degree of freedom for the critical value
dfc = n- 1
dfc = 3 - 1
dfc = 2
At the level of significance ∝ = 0.05
The F critical value from the standard normal F table
i.e
[tex]F_{critical { (2, 27)}=[/tex] 3.35
Hi people if someone gives me a hint please. Show algebraically that the product of two consecutive numbers is always even l wrote n (n+1) is always an even number But doesnt recognise it as 100% right thanks for any help
Answers
Step-by-step explanation:
Consider the following rules.
even + odd = odd
even - odd = odd
even × odd = even
even ÷ odd = even (if divisible)
Now for the two consectives terms...
One will surely be even and the other, odd.
So using the rule
Their product will always be odd
Hope it helps....
BRAINLIEST PRETTY PLEASE!!
If 2x + 5 = 8x, then 12x = ?
A 5
B
10
C
15
D 20
Answers
Answer:
10
Step-by-step explanation:
2x + 5 = 8x
Subtract 2x from each side
2x-2x + 5 = 8x-2x
5 = 6x
We want 12x so multiply each side by 2
2*5 = 6x*2
10 = 12x
Answer:
B. 10
Step-by-step explanation:
To find 12x, you first need to find the value of x using the first equation:
[tex]2x+5=8x[/tex]
You need to get the variables (x) on the same side of the equation in order to simplify them. To do this, use reverse operations. Subtract 2x from both sides to keep the equation balanced:
[tex]2x-2x+5=8x-2x\\\\5=6x[/tex]
Now isolate the variable (x) by dividing both sides of the equation by 6 (using reverse operations):
[tex]\frac{5}{6}=\frac{6x}{6} \\\\\frac{5}{6}=x[/tex]
Now insert the given value of x into 12x:
[tex]12(\frac{5}{6})[/tex]
Simplify:
[tex]12*\frac{5}{6} \\\\\frac{12}{1}*\frac{5}{6}\\\\\frac{60}{6}=10[/tex]
12x equals 10.
:Done
Given a dataset with the following properties:
mean = 50
median = 40
standard deviation = 5
What is the shape of the distribution?
Answers
Answer:
The distribution is positively skewed.
Step-by-step explanation:
A measure of skewness is defined in such a way that the measure should always be zero when the distribution is symmetric and measure should be a pure number i.e independent of origin and units of measurement.
The shape of the distribution can be found by finding the coefficient of skewness.
The coefficient of skewness can be found by
Sk= 3(Mean-Median)/ Standard Deviation
Sk= 3( 50-40)5= 30/5=6
The shape will be positively skewed.
In a positively skewed distribution the mean > median > mode. It has a long right tail.
Using the skewness formula, it is found that the distribution is right-skewed.
------------------
The skewness of a data-set with mean M, median [tex]M_e[/tex] and standard deviation s is given by:[tex]S = \frac{3(M - M_e)}{s}[/tex]
If |S| < 0.5, the distribution is said to be symmetric.If S <-0.5, the distribution is left-skewed.If S > 0.5, the distribution is right-skewed.------------------
Mean of 50, thus, [tex]M = 50[/tex]Median of 40, thus [tex]M_e = 40[/tex]Standard deviation of 5, thus, [tex]s = 5[/tex]The coefficient is:
[tex]S = \frac{3(M - M_e)}{s} = \frac{3(50 - 40)}{5} = \frac{30}{5} = 6[/tex]
Thus, the distribution is right-skewed.
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A box is 30 inches wide, 16 inches long, and 14 inches high. To the nearest cubic inch, what is the volume of the box?
Answers
Answer:
6720 in ^3
Step-by-step explanation:
Volume = length * width * height
= 30*16*14
=6720 in ^3
I dont understand how to do this
Answers
Answer:
Put 25 in the box.
Step-by-step explanation:
Apply the exponent rule: (ax)^n = a^n × x^n
So we have:
(5x)^2 = 5^2 × x^2
= 25x^2
Best Regards!
Identify which equations have one solution, infinitely many solutions, or no solution. No solution: One solution: Infinitely solution:
Answers
Answer:
Top left: no
Top middle: one
Top right: no
Bottom left: infinite
Bottom middle: one
Bottom right: one
Step-by-step explanation:
Top left: no
Top middle: one
Top right: no
Bottom left: infinite
Bottom middle: one
Bottom right: one
Why do interest rates on loans tend to be higher in a strong economy than in a weak one?
Answers
The head of a computer science department is interested in estimating the proportion of students entering the department who will choose the new computer engineering option. Suppose there is not information about the proportion of students who might choose the option. What size sample should the department head take if he wants to be 95% confident that the estimate is within 0.10 of the true proportion
Answers
Answer:
96
Step-by-step explanation:
From the given information:
At 95% Confidence interval level,Level of significance [tex]\alpha[/tex] 0.05, the value of Z from the standard normal tables = 1.96
Margin of Error = 0.10
Let assume that the estimated proportion = 0.5
therefore; the sample size n can be determined by using the formula: [tex]n =(\dfrac{Z}{E})^2 \times p\times (1-p)[/tex]
[tex]n =(\dfrac{1.96}{0.1})^2 \times 0.5\times (1-0.5)[/tex]
[tex]n =(19.6)^2 \times 0.5\times (0.5)[/tex]
n = 96.04
n [tex]\approx[/tex] 96
Su Jean is driving from phoenix to houston. A distance of 1185 miles. After driving for 4 hours she calculates that she has driven 237 miles. What portion of the distance does she have left to drive?
Answers
Answer:
4/5
Step-by-step explanation:
237/1185 = .2 = 1/5
meaning there's 4/5 left
Evaluate the integral using integration by parts with the indicated choices of u and dv. (Use C for the constant of integration.) ∫4x2 lnx dx ; u= lnx , dv=4x 2dx
Answers
Take
[tex]u=\ln x\implies\mathrm du=\dfrac{\mathrm dx}x[/tex]
[tex]\mathrm dv=4x^2\,\mathrm dx\implies v=\dfrac43x^3[/tex]
Then
[tex]\displaystyle\int4x^2\ln x\,\mathrm dx=\frac43x^3\ln x-\frac43\int x^2\,\mathrm dx=\frac43x^3\ln x-\frac49x^3+C[/tex]
[tex]=\boxed{\dfrac49x^3(3\ln x-1)+C}[/tex]
The required integration is,
∫4x² lnx dx = (lnx) [(4/3)x³ + C₁] - (4/9)x³ + C
The given integral is,
∫4x² lnx dx
Using integration by parts, choose u and dv.
In this case, we choose u = lnx and dv = 4x²dx.
Using the formula for integration by parts, we have:
∫ u dv = uv - ∫ v du
Substituting the values of u and dv, we get:
∫4x² lnx dx = (lnx) (∫ 4x² dx) - ∫ [(d/dx)lnx] (∫4x² dx) dx
Simplifying the first term using the power rule of integration, we get:
∫ 4x² dx = (4/3)x³ + C₁
For the second term, we need to evaluate (d/dx)lnx,
Which is simply 1/x. Substituting this value, we get:
∫ [(d/dx)lnx] (∫4x² dx) dx = ∫ [(1/x) ((4/3)x³ + C₁)] dx
Simplifying this expression, we get:
∫4x² lnx dx = (lnx) [(4/3)x³ + C₁] - ∫ [(4/3)x³/x] dx
Using the power rule of integration again, we get:
∫4x² lnx dx = (lnx) [(4/3)x³ + C₁] - (4/9)x³ + C
Where C is the constant of integration.
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A population of values has a normal distribution with μ= 106.9 and σ=14.5
You intend to draw a random sample of size n=20
What is the probability that a single randomly selected value is less than 109.8?
P(X < 109.8)
How do you the probability that a sample of size n= 20 is randomly selected with a mean less than 109.8?
P(M < 109.8)
Also, I have to round the answer to the 4th decimal place. How do I do that?
Answers
Step-by-step explanation:
Find the z-score.
z = (x − μ) / σ
z = (109.8 − 106.9) / 14.5
z = 0.2
Use a chart or calculator to find the probability.
P(Z < 0.2) = 0.5793
Find the mean and standard deviation of the sampling distribution.
μ = 106.9
σ = 14.5 / √20 = 3.242
Find the z-score.
z = (x − μ) / σ
z = (109.8 − 106.9) / 3.242
z = 0.894
Use a calculator to find the probability.
P(Z < 0.894) = 0.8145
In recent years, the interest rates on home mortgages have declined to less than 6%. However, a
recent study shows that the rate charged on credit card debt is more than 14%. A sample of 10 credit
cards showed that the mean rate charged is 15.64% with a standard deviation of 1.561%. At 1% level
of significance, is it reasonable to conclude the mean rate charged is greater than 14%?
Answers
Answer:
Yes it is reasonable to conclude the mean rate charged is greater than 14%
Step-by-step explanation:
From the question we are told that
The population mean is [tex]\mu = 0.14[/tex]
The sample size is [tex]n = 10[/tex]
The sample mean is [tex]\= x = 0.1564[/tex]
The standard deviation is [tex]\sigma = 0.01561[/tex]
The level of significance is [tex]\alpha = 0.01[/tex]
The null hypothesis is [tex]H_o: \mu = 0.14[/tex]
The alternative hypothesis is [tex]H_a : \mu > 0.14[/tex]
Generally the test statistic is mathematically represented as
[tex]t = \frac{ \= x - \mu }{ \frac{\sigma }{\sqrt{n} } }[/tex]
substituting values
[tex]t = \frac{ 0.1564 - 0.14 }{ \frac{0.01561 }{\sqrt{10} } }[/tex]
[tex]t = 3.322[/tex]
Now the p-value obtained from the z-table is
[tex]p-value = P(t > 3.322) = 0.00044687[/tex]
Since the [tex]p-value < \alpha[/tex] then we reject the null hypothesis, hence we can conclude that the mean rate charged is greater than 14%
