Quiz 7

Hypothesis testing of single samples z-test and t-test

1. Which of the following pair of statistical hypotheses is NOT valid?

a) H0: μ = 82 kg H1: μ ≠ 82 kg

b) H0: μ ≥ 82 kg H1: μ < 82 kg

c) H0: μ < 82 kg H1: μ > 82 kg

d) H0: μ ≤ 82 kg H1: μ > 82 kg

2. The diagram at bottom is an example of a ________ test.

a) one-tailed, rightb) two-tailedc) directionald) one-tailed, left

Non-criticalregion

Criticalregions

3. What does mean?

a) probability of a Type I errorb) probability of a Type II errorc) power of a statistical testd) area in non-critical region

4. Power of a statistical test is defined _______.

a) by 1 — b) by c) as chance of getting a Type I errord) as the ability to detect a real difference

5. The z-distribution should be used to test a sample mean when ______.

a) is known b) sample size is < 30c) data are not normally distributedd) sample size is > 30

6. The t-test for testing a single sample mean may be used when all of the following conditions are true excepting _______.

a) data are approximately normally distributedb) population SD () is knownc) sample size less than 30d) sample SD (s) is known

7. Given a population with mean 12.5 seconds and SD of 2.5 s, calculate the test value of a sample of 20 people with a mean of 13.6 s representative of the population? Use =0.05.

a) -1.100b) -1.968c) 1.968d) 1.100

8. A sample of 12 scores has a mean of 25.0 newtons with SD of 5.8 N. Given a pop. mean of 30.0 N what test value should be use to test whether it is the same as the pop. mean (=0.05)?

a) 8.37b) 1.783c) -1.783d) -5.00