90% of the people who have a particular disease will have a positive result on a given diagnostic test 90% of the people who do not have the disease will have a negative result on this test is 5% of a certain population has a disease what percent of the population would test positive for the disease

The difference of sample means of two populations is 55.4, and the standard deviation of the difference of sample means is 28.1. which statement is true if we are testing the null hypothesis at the 95% confidence level? a. the difference of the two means is significant, so the null hypothesis must be rejected. b. the difference of the two means is significant, so the null hypothesis must be accepted. c. the difference of the two means is not significant, so the null hypothesis must be rejected. d. the difference of the two means is not significant, so the null hypothesis must be accepted.