Past sales data for a company indicates that the average sale was $120 per transaction with a standard deviation of $15. The company provided enhanced training for the new sales force and recorded the amount for 48 transactions. The results are shown below.
n mean sd min Q1 median Q3 max 48 130.26 17.6 12.80 67.45 107.10 180.5 317.2
Did, at the 10% level, the training result in an increase in the mean transaction amount? Make sure to provide explicit answers with your work shown for all 11 steps of a hypothesis test.
Recurrence of Cancer Tumors
Unfortunately, certain kinds of tumors tend to recur. Byar and Blackard (1977) examined the rate of recurrence for bladder cancer following chemotherapy. Specifically, they recorded the time of recurrence (in months) for patients that received a placebo. Assume that it was known that the population distribution was strongly right-skewed and the standard deviation was 15 months. Use the data in Tumors.csv to determine, at the 10% level, if the mean length of tumor recurrence is greater than 27 months. Make sure to provide explicit answers with your work shown for all 11 steps of a hypothesis test.