Alex's times for running a mile are Normally distributed with a mean time of 5.28 minutes and a standard deviation of 0.38 seconds. Chris's times for running a mile are Normally distributed with a mean time of 5.45 seconds and a
standard deviation of 0.2 seconds. Ten of Alex's times and 15 of Chris's times are randomly selected. Let 5,-
represent the difference in the mean times for Alex and Chris. Which of the following represents the shape of the
sampling distribution for 3-5?
Normal, because both population distributions are Normal.
Uniform, because the both sample sizes are less than 30.
Skewed right, because the difference in times cannot be negative.
Skewed left, because the sample sizes are less than 30 and the sampling variability is unknown.