Question: As part of the National Health and Nutrition Examination Survey (NHANES), hemoglobin levels were checked fro a sample of 1139 men age 70 and over. The sample mean was 145.3 g/l and the standard deviation was 12.87 g/l.

a) use this data to construct a 95% confidence interval for the mean.

b) Does the confidence interval from part a give limits in which we expect 95% of the sample data to lie? Why or why not?

c) Does the confidence interval from part a give limits in which we expect 95% of the population to lie? Why or why not?

d) One world expert claims that mean hemoglobin in this population is 146g/l and another claims that it is 147g/l. Which of these claims are consistent / inconsistent with the data? Answer the question two ways:

i. By referring to appropriate confidence interval(s).

ii. By performing appropriate statistical tests.

e) Classify each of the following as “not unusual”, “unusual”, “most unusual”, giving (appropriate) reasons.

i. A 73 year-old man with hemoglobin level 175 g/l. ii. A 73 year-old man with hemoglobin level 165 g/l.

iii. Three men aged 70 or older with average hemoglobin level 165 g/l.

f) List all values μ0 which would be rejected, at level of significance 0.05, by the test for H0 :μ=μ0

Ha :μ does not equal μ0