Mathematics, 09.04.2021 02:50, ajames2182

A 20-question multiple choice quiz has five choices for each question. Suppose that a student just guesses, hoping to get a high score. The teacher carries out a hypothesis test to determine whether the student was just guessing. The null hypothesis is p = 0.20, where p is the probability of a correct answer. a. Which of the following describes the value of the z-test statistic that is likely to result? Explain your choice.

i. The z-test statistic will be close to 0.
ii. the z-test statistic will be far from 0.

b. Which of the following describes the p-value that is likely to result? Explain your choice.

i. The p-value will be small.
ii. The p-value will not be small.

Answers: 2

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Answers

a) i. The z-test statistic will be close to 0, as the sample mean and the tested proportion are expected to be close values.

b) ii. The p-value will not be small, as the z-statistic is close to 0.

Step-by-step explanation:

The null hypothesis is p = 0.20

The teacher carries out a hypothesis test to determine whether the student was just guessing.

Test if the proportion is different from 0.2. So the alternate hypothesis is:

$H_{a}: p \neq 0.2$

Five choices for each question, one of which is correct.

Probability of having a correct answer is $X = \frac{1}{5} = 0.2$

The test statistic is:

$z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}$

In which X is the sample mean, $\mu$ is the value tested at the null hypothesis, $\sigma$ is the standard deviation and n is the size of the sample.

a. Which of the following describes the value of the z-test statistic that is likely to result?

In this question, $X = p = \mu$ , which meas that the numerator of the z-statistic will be close to 0, which means that the z-test statistic will be close to 0.

b. Which of the following describes the p-value that is likely to result?

pvalue is 2 multiplied by the pvalue of Z(if negative), or 1 subtracted by the pvalue of Z(if positive).

Since the value of Z is close to 0, either the pvalue of Z or 1 subtracted by the pvalue of Z is close to 0.5, and multiplied by 2 will be close to 1. So, as Z is close to 0, the pvalue will not be small.

answered: Guest

first option

a function is a relation in which an input is paired with exactly one output.

so, let's find the right answer.

in our first option, our inputs are january, february, and march. the outputs are 30, 28, and 25. each input has it's own output. this is correct!

our second option we know is incorrect, because ms. valverade has two outputs, dogs and cats. this is not a function.

our third option is incorrect as well. the yellow square has two ouputs, the square and the triangle.

lastly, in our fourth option, we see the number 7 two times with a different output. therefore, this is not a function.

remember: each input must be paired with only one output!