91影视

The sample size is 200, the sample mean is 2.95, and the sample standard deviation is 8.82.

Also, MINITAB output is as follows

a.

Null hypothesis:

\({H_0}:\mu = 0\)

That is, the population of institutional investors performed successfully.

Alternative hypothesis:

\({H_a}:\mu > 0\)

That is, the population of institutional investors did not perform successfully.

b.

Here, the test is the right tail, and the significance level is 0.05. The critical value \({z_{0.05}}\) is obtained from the standard normal table.

Thus, the required \({z_{0.05}}\) critical value is 1.645.

The rejection region for the right tail test is\({z_c} > {z_a}\)

Hence, the rejection region is \({z_c} > 1.645\).

c.

The probability of Type I error is denoted as\(\alpha \). In other words, it is the probability of the error committed to rejecting a null hypothesis\(\left( {{H_0}} \right)\)when it is true.

In the study, the interpretation \(\alpha \) is that the probability of the population of institutional investors did not perform successfully. That is, the probability of the true mean rate of return of round-trip trades is positive.

d.

From the MINITAB output, the test statistic is 4.73, and the p-value is 0.000.

e.

Here, the p-value is 0.000, which is less than the value \(\alpha = 0.05\).

If the p-value <\(\alpha \), then the null hypothesis is rejected.

Hence, Reject the null hypothesis\({H_0}\)

Thus, it can be concluded that the population of institutional investors did not perform successfully at the significance level\(\alpha = 0.05\).

That is, the true mean rate of return of round-trip trades is positive. \(\)