Johannah I. answered • 12/19/19

Experienced Math Tutor

The null hypothesis is p=0.15

The alternative hypothesis is p<0.15

The test statistic is -3.827. This can be calculated using a 1-PropZTest.

The p-value for the problem is 0.00006.

At both the 0.01 and 0.05 level, there is sufficient evidence to support the claim that less than 15% of US adults have a great deal of confidence in banks. This can be determined using the p-value:

If p<*α* then reject the null

If p>*α* then fail to reject the null

It can also be determined using the test statistic.

If the test statistic for a left-tailed test is less than the z score for each given *α* then then null hypothesis is rejected

If the test statistic for a left tailed test is greater than the z score for each given *α* then fail to reject the null hypothesis.