Mathematics, 22.04.2020 16:01 EMQPWE

Historically, the mean yield of corn in the United States has been 120 bushels per acre with a standard deviation of 12. A survey of 40 farmers this year gives a sample mean yield of 125 bushels per acre . Let p be the mean yield of corn nationally for this year. Supposing that the past standard deviation is still correct, what is the p-value for testing a null hypothesis of mu=120 against an alternative of mu not equal to 20 ? A 0.0041 B 0.0082 C 2.64 D 125

Answers: 1

Show answers

Answers

Answer from: emilysambrano2

$z=\frac{125-120}{\frac{12}{\sqrt{40}}}=2.64$

P-value

Since is a two sided test the p value would be:

p_v =2*P(z2.64)=0.0082

And the best answer would be

B 0.0082

Step-by-step explanation:

Data given and notation

$\bar X=125$ represent the mean height for the sample

$\sigma=12$ represent the population standard deviation

n=40 sample size

$\mu_o =120$ represent the value that we want to test

$\alpha$ represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

p_v represent the p value for the test (variable of interest)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the true mean is 120 or not, the system of hypothesis would be:

Null hypothesis: $\mu = 120$

Alternative hypothesis: $\mu \neq 120$

If we analyze the size for the sample is > 30 and we know the population deviation so is better apply a z test to compare the actual mean to the reference value, and the statistic is given by:

$z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}$ (1)

z-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Calculate the statistic

We can replace in formula (1) the info given like this:

$z=\frac{125-120}{\frac{12}{\sqrt{40}}}=2.64$

P-value

Since is a two sided test the p value would be:

p_v =2*P(z2.64)=0.0082

And the best answer would be

B 0.0082

Answer from: Quest

what does x eaqual

step-by-step explanation:

Answer from: Quest

5x + 3y = - 4

step-by-step explanation:

the equation of a line in standard form is

ax + by = c ( a is a positive integer and b, c are integers )

express the line first of all in slope- intercept form

y = mx + c ( m is the slope and c the y-intercept )

to calculate m use the gradient formula

m = ( y₂ - y₁ ) / ( x₂ - x₁ )

with (x₁, y₁ ) = (7, - 3) and (x₂, y₂ ) = (4, - 8)

m = $\frac{-8+3}{4-7}$ = - $\frac{5}{3}$

y = - $\frac{5}{3}$ x + c ← is the partial equation

to find c substitute either of the 2 points into the partial equation

using (4, - 8 ), then

- 8 = - $\frac{20}{3}$ + c ⇒ c = - $\frac{4}{3}$

y = - $\frac{5}{3}$ x - $\frac{4}{3}$ ← in slope-intercept form

multiply all terms by 3 to eliminate the fractions

3y = - 5x - 4 ( add 5x to both sides )

5x + 3y = - 4 ← in standard form

Another question on Mathematics

Mathematics, 21.06.2019 17:00

Use the frequency distribution, which shows the number of american voters (in millions) according to age, to find the probability that a voter chosen at random is in the 18 to 20 years old age range. ages frequency 18 to 20 5.9 21 to 24 7.7 25 to 34 20.4 35 to 44 25.1 45 to 64 54.4 65 and over 27.7 the probability that a voter chosen at random is in the 18 to 20 years old age range is nothing. (round to three decimal places as needed.)

Answers: 1

Answer

Mathematics, 21.06.2019 23:00

Divide. –40 ÷ –5 a –8 b 200 c -200 d 8

Answers: 1

Answer

Mathematics, 22.06.2019 02:00

Atriangle has vertices of (0,3.5), (3,1.5), (0, -1.5). if it is dilated with center at the origin, and a scale factor of 2, what will be the coordinates of the image?

Answers: 3

Answer

Mathematics, 22.06.2019 03:30

Use the method of cylindrical shells to find the volume v generated by rotating the region bounded by the given curves about y = 8.8y = x3, y = 0, x = 4use the method of cylindrical shells to find the volume v generated by rotating the region bounded by the given curves about y = 8.8y = x3, y = 0, x = 4

Answers: 1

Answer

You know the right answer?

Historically, the mean yield of corn in the United States has been 120 bushels per acre with a stand...

Questions