Problem 23.3: Describe how the shape, centre, and spread of t-
models change as the number of degrees of freedom
Problem 23.7: After surveying students at Darmouth College, a
campus organization calculated that a 95% confidence interval
for the mean cost of food for one term (of three in the
Dartmouth trimester calendar) is ($1102, $1290). Now the
organization is trying to write its report and is considering the
a) 95% of all students paid between $1102 and $ 1290 for
b) 95% of the sampled students paid between $1102 and $
c) We are 95% sure that students in this sample averaged
between $1102 and $ 1290 for food.
d) 95% of all samples of students have average food costs
between $1102 and $1290.
e) We’re 95% sure that the average amount all students pay
is between $1102 and $1290.
Problem 23.9 : A medical researcher measured the pulse
rates (beats per minute) of a sample of randomly selected
adults and found the following Students’s t-based
With 95% Confidence