It is advertised that the average braking distance for a small car traveling at 65 miles per hour equals 120 feet. a transportation researcher wants to determine if the statement made in the advertisement is false. she randomly test drives 34 small cars at 65 miles per hour and records the braking distance. the sample average braking distance is computed as 115 feet. assume that the population standard deviation is 20 feet.
state the null and the alternative hypotheses for the test.