1. Use the output shown in Figure 9.8 for a new data set to decide which decision is appropriate for a two-tailed test with an alpha level of 0.05: to reject or retain the null hypothesis. 2. When we...

1. Use the output shown in Figure 9.8 for a new data set to decide which decision is appropriate for a two-tailed test with an alpha level of 0.05: to reject or retain the null hypothesis.

2. When we do not know the population σ, we use the _______________ to calculate estimate standard error.

a. population mean

b. sample mean

c. sample standard deviation

d. sampling error