Researchers studying infant head circumferences (in centimeters) wish to test if the mean head circumference differs from the historical mean of 34.5 cm. The researchers obtain a sample of 17 infants with a mean head circumference of 34.16 cm and a standard deviation of 0.58 cm. At the α = 0.05 significance level, test the claim HO: µ = 34.5 HA: µ ≠ 34.5

a) Is this an upper tail, lower tail, or two-tail test?

b) Are we testing means or proportions?

c) State the rule of rejection (in terms of p-value and level of significance)

d) Find the p-value

e) Should you reject or not reject HO?

f) Does the result suggest that the mean head circumference differs from 34.5 cm?