I’m studying for my Statistics class and need an explanation.
A man in Oakwood who live near the local high school recorded the speeds of cars driving past his house, where the speed limit is posted at 25 mph. The mean of a sample of 100 recorded speeds was 28.84 mph with a standard deviation of 3.15 mph.
a. What is the z-score of a car going 35 mph?
b. What is the z-score of a car going 23 mph?
c. Assuming an approximately distribution of car speeds, which would be more unusual, the car going 35 mph or the car going 23 mph? Explain.