Find f(-2) for f(x) = 3.2%

An English professor assigns letter grades on a test according to the following scheme. A: Top 9% of scores B: Scores below the

sergeinik [125]

Answer:

The minimum score required for an A grade is 83.

Step-by-step explanation:

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the z-score of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

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.

Mean of 72.3 and a standard deviation of 8.

This means that $\mu = 72.3, \sigma = 8$

Find the minimum score required for an A grade.

This is the 100 - 9 = 91th percentile, which is X when Z has a pvalue of 0.91, so X when Z = 1.34.

$Z = \frac{X - \mu}{\sigma}$

$1.34 = \frac{X - 72.3}{8}$

$X - 72.3 = 1.34*8$

$X = 83$

The minimum score required for an A grade is 83.

5 0

2 years ago

Select the correct answer.

gtnhenbr [62]

Answer:

5 years

Step-by-step explanation:

To determine the number of years needed for the company to process a certain amount of milk, we use the given function which relates the number of years, x, and the gallons of milk, y. We simply substitute the number of gallons to y and solve for x.

y = x^6 − 9x^4 + 70x^2

630 = x^6 − 9x^4 + 70x^2

Solving for x, we will have

x = 4.8866 years or approximately 5 years

Hope this answer helps you :)

Have a great day

Mark brainliest

7 0

2 years ago

Step 1 of 3: Each year a nationally recognized publication conducts its Survey of America’s Best Graduate and Professional Schoo

lukranit [14]

Answer:

Step-by-step explanation:

Hello!

Given the variables

Y: Starting salary of a graduate at a top business school

X: GMAT score of the business school

The sample used had a size n=20

The estimated regression equation was ^Y= -92040 + 228Xi

The correlation coefficients were r= 0.81

You need to know if r is statistically significant at a 0.05 level:

Assuming the hypotheses are:

H₀: There is a linear correlation between the variables of interest

H₁: There is no linear correlation between the variables of interest

α: 0.05

This test is two-tailed.

The p-value for a r=0.81 and n=20 is 0.000015

Using the p-value approach, the decision rule is:

If p-value ≤ α, reject the null hypothesis

If p-value > α, do not reject the null hypothesis

In this case, the p-value is less than α, the decision is to reject the null hypothesis.

At a 5% level, you can conclude that the coefficient of correlation is statistically significant.

4 0

3 years ago

2^x-1=128 show work pls! thank u :)

hichkok12 [17]

Hello from MrBillDoesMath!

Answer:

Take you pick below! (either x 8 or x = 7.01, approx, depending how the question is interpreted)

Discussion:

Interpretation 1

If the question is 2^(x -1) = 128, then as 2^7 = 128,

x-1 = 7 so x = 8

Interpretation 2

If the question is (2^x -1) = 128, then..

2^x = 128 + 1 = 129 =>

log(2^x) = log(129) =>

xlog(2) = log(129) =>

x = log (129) / log2 = 7.01

Regards,

MrB

4 0

3 years ago

What is the equation of the line perpendicular to 3x+y= -8that passes through -3,1? Write your answer in slope-intercept form. S

Gekata [30.6K]

Slope intercept form of a line perpendicular to 3x + y = -8, and passing through (-3,1) is $y=\frac{1}{3} x+2$

Solution:

Need to write equation of line perpendicular to 3x+y = -8 and passes through the point (-3,1).

Generic slope intercept form of a line is given by y = mx + c

where m = slope of the line.

Let's first find slope intercept form of 3x + y = -8

3x + y = -8

=> y = -3x - 8

On comparing above slope intercept form of given equation with generic slope intercept form y = mx + c , we can say that for line 3x + y = -8 , slope m = -3

And as the line passing through (-3,1) and is perpendicular to 3x + y = -8, product of slopes of two line will be -1 as lies are perpendicular.

Let required slope = x

$\begin{array}{l}{=x \times-3=-1} \\\\ {=>x=\frac{-1}{-3}=\frac{1}{3}}\end{array}$

So we need to find the equation of a line whose slope is $\frac{1}{3}$ and passing through (-3,1)

Equation of line passing through $(x_1 , y_1)$ and having lope of m is given by

$\left(y-y_{1}\right)=\mathrm{m}\left(x-x_{1}\right)$

$\text { In our case } x_{1}=-3 \text { and } y_{1}=1 \text { and } \mathrm{m}=\frac{1}{3}$

Substituting the values we get,

$\begin{array}{l}{(\mathrm{y}-1)=\frac{1}{3}(\mathrm{x}-(-3))} \\\\ {=>\mathrm{y}-1=\frac{1}{3} \mathrm{x}+1} \\\\ {=>\mathrm{y}=\frac{1}{3} \mathrm{x}+2}\end{array}$

Hence the required equation of line is found using slope intercept form

4 0

2 years ago