You know the mean and standard deviation of a population. You take a sample from this population and compute the 90% CI for the mean. This interval contains values that are within how many standard deviations of the mean?

Answer choices:

.90

1.49

1.65

1.83

Soda Tak claims that Diet Tak has 40mg of sodium per can. You work for a consumer organization that tests such claims. You take a random sample of 60 cans and find that the mean amount of sodium in the sample is 41.9mg. The population standard deviation in all cans is 5.2mg. You suspect that there is more than 40mg of sodium per can. Find the z-score.

Answer choices:

1.3749

1.5062

2.830

2.910