Question

1. Why would a one-sample t-test be used over a z-test?

a. when the population mean is not known

b. when the population variability is not known

c. when the test is using a 1% significance level instead of 5%

d. if there are outliers present in the data '

2.Explain why you would conduct a paired-samples t-test.

Answer 1

1.If the population mean is unknown hence t-distribution is applicable for hypothesis testing.

2.With paired data we are interested in the difference between each paired value of the same objects before and after some influence.