A car manufacturer crash tests a certain model of car and measures the impact force. The test and model in question produce impa
ct forces that are normally distributed with a mean of 303030 metric tons and a standard deviation of 1.51.51, point, 5 metric tons. Suppose that the manufacturer tests a random sample of 444 cars and calculates the sample mean impact force.
Since the impact force in the test model is normally distributed, the shape of the sampling distribution will also be approximately normal with a mean equal to the mean of the test model.
Hence, the sample mean impact force will be equal to the population mean.
Therefore, sample mean = 30 ; population mean = 30
