In a goodness-of-fit test, the null hypothesis states that the data came from a normally distributed population. The researcher estimated the population mean and population standard deviation from a sample of 500 observations.

In addition, the researcher used 6 standardized intervals to test for normality.

Using a 5% level of significance, the critical value for this test is:

a. 11.1433.
b. 9.3484.
c. 7.8147.
d. 9.4877.