PubH 6002

Lab Exercise 4

1.A researcher claims that women who eat blue M&M candies have a better chance of having a baby boy, and 50 such women gave birth to 27 boys and 23 girls. What conclusion should be drawn? Use only the rare event rule and make a subjective estimate to determine whether the event is likely. Do not use formal procedures or exact calculations here.

2.For the following, write out the claim that is suggested along with an appropriate conclusion about the claim. Do not use symbolic expressions or formal procedures here. Instead, use common sense.

a.The rate of Lyme disease cases in Clinton County is 2%. When 1000 people from that county are given a placebo, it is found that 22 of them contract Lyme disease. When 1000 people from that county are given a new experimental vaccine, it is found that 18 of them contract Lyme disease.

b.In a test of the polio vaccine, 200,000 children are given a placebo and 200,000 other children are given the Salk vaccine. Among those in the placebo group, 115 later develop polio. Among those given the Salk vaccine, 33 later develop polio.

3.The nighttime cold medicine Dozenol bears a label indicating the presence of 600 mg of acetaminophen in each fluid ounce of the drug. The Food and Drug Administration randomly selected 40 one-ounce samples and found that the mean acetaminophen content is 593 mg with standard deviation 21 mg. Using a significance level of 0.01, test the claim of the Medassist Pharmaceutical Company that the population mean is equal to 600 mg. Assume the amounts are approximately normally distributed.

4.A New York Times article noted that the mean life span for 35 male symphony conductors was 73.4 years, in contrast to the mean of 69.5 years for males in the general population. Assuming that all males in the population have approximately normally distributed life spans with a standard deviation of 8.7 years, use a 0.05 significance level to test the claim that male symphony conductors have a mean life span that is different from 69.5 years.

5.When a poultry farmer uses her regular feed, the newborn chickens have normally distributed weights with a mean of 62.2 oz. In an experiment with an enriched feed mixture, 9 chickens are born with the following weights (in ounces):

61.4

62.2

66.9

63.3

66.2

66.0

63.1

63.7

66.6

Using a 0.01 significance level, test the claim that the mean weight with the enriched feed is higher than 62.2 oz.