Question

A set of sample scores from an experiment has an N = 28 and a mean = 52. H 1 is directional, predicting an effect of the independent variable which decreases the magnitude of the dependent variable. H 0 asserts the sample is a random sample from a population of scores where µ = 55 and s = 12. a = 0.051 tail. Using the z test to analyze the data, z crit = _________.

PLEASE EXPLAIN HOW YOU GOT YOUR ANSWER

Answer 1

Sample size = n = 28

Sample mean = = 52

Population standard deviation = = 12

The null and alternative hypothesis is

Level of significance = 0.05

Here population standard deviation is known so we have to use z-test statistic.

Test statistic is

Critical value = 1.64 ( Using z table)

Critical value > Test statistic | z | we fail to reject the null hypothesis.

Conclusion: The population mean is 55.