Question 1

Which of the following best describes the main benefit of standardizing scores using the z table?

Accepted Answer

It allows for fair comparisons across different distributions.

Question 2

A researcher wants to know the percentage of scores above a raw score in a normal distribution. What is the correct sequence of steps?

Accepted Answer

Convert the raw score to a z score, look up the area in the z table, subtract from 100%.

Question 3

Given a z score of $z = 1.00$, what percentage of scores fall between the mean and this z score in a standard normal distribution?

Accepted Answer

$34.13\%$

Question 4

If a student’s test score is at the 90th percentile, what is the first step to find the corresponding z score?

Accepted Answer

Use the z table in reverse to convert the percentile to a z score.

Question 5

Why is sketching the normal curve considered a useful practice in hypothesis testing?

Accepted Answer

It helps minimize errors and serves as a practical reference.

Question 6

Which formula is used to convert a raw score $X$ to a z score?

Accepted Answer

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

Question 7

A hospital administrator wants to know if the average recovery time for a new treatment is significantly different from the national average. Which hypothesis test should be used if the population mean and standard deviation are known?

Accepted Answer

A z test

Question 8

Which of the following is NOT an assumption required for conducting a parametric hypothesis test?

Accepted Answer

The population mean must be zero.

Question 9

What does it mean if a result is 'statistically significant'?

Accepted Answer

The observed data differ from what would be expected by chance if there were no actual difference.

Question 10

Which of the following best describes a one-tailed hypothesis test?

Accepted Answer

The research hypothesis predicts a mean increase or decrease, but not both.

Question 11

A psychologist is interested in whether a new therapy changes anxiety levels but does not predict the direction of change. Which test should be used?

Accepted Answer

A two-tailed hypothesis test

Question 12

Which of the following is the correct formula for converting a z score back to a raw score $X$?

Accepted Answer

$X = z \sigma + \mu$

Question 13

Which of the following is an example of p-hacking?

Accepted Answer

Running multiple analyses and only reporting those that are statistically significant.

Question 14

What is the main difference between parametric and nonparametric tests?

Accepted Answer

Parametric tests are based on assumptions about the population; nonparametric tests are not.

Question 15

Which step in hypothesis testing involves calculating the test statistic?

Accepted Answer

Step 5

Question 16

A sample mean is 110, the population mean is 100, and the population standard deviation is 15. What is the z score for the sample mean?

Accepted Answer

$z = \frac{110 - 100}{15} = 0.67$

Question 17

If a z score is $-1.82$, what percentage of scores fall below this value in a standard normal distribution?

Accepted Answer

$3.44\%$

Question 18

Which of the following is NOT a step in the six-step hypothesis testing procedure?

Accepted Answer

Calculate the sample variance.

Question 19

A researcher finds a statistically significant result but the effect size is very small. What does this imply?

Accepted Answer

The result may not be practically meaningful.

Question 20

Which of the following best describes HARKing?

Accepted Answer

Formulating hypotheses after results are known and presenting them as if they were made a priori.

Chapter 7: Hypothesis Testing with z Tests – Mini-Textbook Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards