1) Which of the following statements expresses a major difference between the hypothesis test using the

formula for z and the one using t on a sample? (1 point)

a) You need to know the standard deviation of the sample to calculate a t, but not to calculate

a z.

b) You need to know the standard deviation of the population to calculate a z, but not to calculate

a t.

c) Items a) and b) present two major differences between the hypothesis test

using the formula for z and the one using t.

d) None of these statements express a major difference between the hypothesis test

using the formula for z and the one using t.

2) In which of the following situations is the most likely to use an independent test?

(1 point)

a) Evaluate the effectiveness of a drug by measuring how much pain is reduced after

its consumption.

b) Evaluate vocabulary improvement in a group of children between their first year

and their second school year.

c) Assess the difference in self-esteem between athletes and non-athletes.

d) To assess the effectiveness of Cheerios in lowering cholesterol levels.