In: Statistics and Probability
A company is developing a new high performance wax for cross country ski racing. In order to justify the price marketing wants, the wax needs to be very fast. Specifically, the mean time to finish their standard test course should be less than 55 seconds for a former Olympic champion. To test it, the champion will ski the course 8 times. The champion's times (selected at random) are 56.4, 60.4, 48.548.5, 53.3, 49.9, 46.9, 53.7, and 42.1 seconds to complete the test course. Should they market the wax? Assume the assumptions and conditions for appropriate hypothesis testing are met for the sample. Use 0.05 as the P-value cutoff level.
We find the mean and standard deviation of the given data :
Here, we conduct the t-test for one population mean as :
Hence, we conclude that the wax should not be marketed as mean time to finish their standard test course is not less than 55 at 5% level of significance.