Malaria is a disease spread by mosquitos. Researchers want to test a potential vaccine for the disease, so they plan on recruiting thousands of subjects from each of the 10 countries that are most affected by the disease. The researchers want to use a randomized block design where some subjevrw receive the vaccine and the rest receive a placebo. How should the researchers from the blocks?
Choose 1
A) Each subject should be randomly assigned to a block.
B) Both the subjects and researchers should be kept blind as to which block the subjects are in.
C) Each block should consist of subjects who like in the same country.
D) Subjects in one block should get the vaccine, while subjects in the other block should get the placebo.
E) Each block should consist of subjects who live in different countries.

Arecent study focused on the number of times men and women who live alone buy take-out dinner in a month. assume that the distributions follow the normal probability distribution and the population standard deviations are equal. the information is summarized below. statistic men women sample mean 24.85 21.33 sample standard deviation 5.54 4.93 sample size 34 36 at the 0.01 significance level, is there a difference in the mean number of times men and women order take-out dinners in a month? state the decision rule for 0.01 significance level: h0: μmen= μwomen h1: μmen ≠ μwomen. (negative amounts should be indicated by a minus sign. round your answers to 3 decimal places.) compute the value of the test statistic. (round your answer to 3 decimal places.) what is your decision regarding the null hypothesis? what is the p-value? (round your answer to 3 decimal places.)