Critical Thinking Explain hypothesis testing to a friend, using the following scenario as a model.

Describe the hypotheses, the sample statistic, the P-value, the meanings of type I and type II errors, and the level of signifi cance. Discuss the signifi cance of the results. Formulas are not required.

A team of research doctors designed a new knee surgery technique utilizing much smaller incisions than the standard method. They believe recovery times are shorter when the new method is used. Under the old method, the average recovery time for full use of the knee is 4.5 months. A random sample of 38 surgeries using the new method showed the average recovery time to be 3.6 months, with sample standard deviation of 1.7 months. The P-value for the test is 0.0011. The research team states that the results are statistically signifi cant at the 1% level of signifi cance.