Question

1) A sample of cereal boxes is randomly selected and the sugar contents (grams of sugar per gram of cereal) are recorded. Those amounts are summarized with these statistics: n = 16, ?̅ = 0.295g, s = 0.168g. Use a 0.05 significance level to test the claim that the mean of all cereals is less than 0.3g.

Section 7-6 Problem
Testing a Claim about a Standard Deviation

a ) Use a 0.05 significance level to test the claim that heights of female actress vary less than the heights of women in general. The standard deviation of heights of the population of women is 2.5 in. Listed below are the heights (in inches) of 18 randomly selected actresses.

Testing a Claim about a Mean: σ is known

b) When people smoke, the nicotine they absorb is converted to cotinine, which can be measured. A sample 40 smokers has a mean cotinine level of 172.5. Assuming that σ is known to be 119.5, use a 0.01 significance level to test the claim that the mean cotinine level of all smokers is equal to 200.0.

71 71 70 69 69.5 70.5 71 72 70

70 69 69.5 69 70 70 66.5 70 71 The standard deviation of the 18 heights is 1.187 in.

Answer 1