Chapter 9, Problem 82CRE

Choose a $t\text{-test}$ for each situation: one-sample $t\text{-test}$, two-sample $t\text{-test}$, paired $t\text{-test}$, and no $t\text{-test}$.

A random sample of car dealerships is obtained. Then a student walks onto each dealer’s lot wearing old clothes and finds out how long it takes (in seconds) for a salesperson to approach the student. Later the student goes onto the same lot dressed very nicely and finds out how long it takes for a salesperson to approach.

A researcher at a preschool selects a random sample of 4-year-olds, determines whether they know the alphabet (yes or no), and records gender.

A researcher calls the office phone for a random sample of faculty at a college late at night, measures the length of the outgoing message, and records gender.