1) When we reject the null hypothesis, we have evidence that the difference observed is

Group of answer choices

a Type I error.

due to chance;

not likely the result of chance;

very small;

2)

A one-tailed test is proper when

Group of answer choices

you do not have enough data for a two-tailed test;

you are only interested in finding out if the effect of a treatment is to increase the scores;

you want to make the standard error of a difference as small as possible.

you have only one sample, not two;

3) You predicted that your sample mean will be greater than the population mean. You conducted a null hypothesis testing using the z test at the alpha level of .01. When your conclusion begins with "Fail to reject the Null Hypothesis...", it is because you obtained a Z score that is

Group of answer choices

less than 1.96

greater or lesser than 1.645

greater or lesser than 2.33

less than 1.645

less than 2.33

greater or lesser than 1.96