An experiment was conducted to test the effect of a new drug on a viral infection. The infection was included in 100 mice and the mice were randomly split into two groups of 50. The first group, the control group, received no treatment for the infection. The second group received the drug. After a 30-day period, the proportions of survivors, 1 and 2, in the two groups were found to be 0.36 and 0.60, respectively. For testing the effectiveness of the treatment, we set the test of hypotheses Ho P1 P2 = 0, versus and use the following value: = 0.05 . 1. The standardized observed statistic is H P1 P2 < 0 2. The critical value that characterizes the critical region of the test is : 3. The observed statistic (enter a or b) a. falls in the critical region b. doesn't fall in the critical region 4. Use the table to find the closest lower and upper bounds of the p-value. < p-value < 5. A \(95% confidence interval for the true mean difference would be in the form (complete the missing numbers with 3 decimals) Confidence interval = \( z_{\alpha/2}\). ( ) 6. Select the correct conclusion. c. There is a significant difference between the two population proportions. d. We cannot conclude that there is a significant difference between the two population proportions. (enter c or d)