Investigators hypothesize that the blood level of a certain enzyme is different between people who suffer from disease X and normal healthy volunteers without the disease. The measure the enzyme level in two groups of people. The first group is the case group (subjects suffer from disease X) and the second group is the control group (normal healthy volunteers). The number of subjects in the first group is 25 and in the second group it is 20. The mean enzyme level in the first group is 25 with a standard deviation of 4. The mean enzyme level in the second group is 20 with a standard deviation of 5. Does this experiment provide evidence for the investigator's hypothesis? Perform an independent sample t-test (also called two-sample t-test and the student's t-test) assuming independent samples, normality of data, equality of variance and significance level (alpha) = 0.05. (Show your calculations. Without calculations, you will not receive any credit for this question). State the null and alternative hypotheses Calculate the t-statistic from the data provided Using the t-table provided in this week's presentation, find out the p-value for this test. (you will not be able to find the actual p-value from the table, but only two values between which the actual p-value lies) State your inference. We can clearly see that the mean enzyme level in the first group is higher than that of the second group. Why do a statistical test to determine if there is a difference