Refer to the previous exercise. Now test whether the population mean amount spent differs among the three

Question:

Refer to the previous exercise. Now test whether the population mean amount spent differs among the three groups, using α = 0.01. Describe any conflict between your two conclusions. Suggest at least two courses of action to ameliorate the situation.

Data From previous Exercise

Contains the amount spent (in dollars) in a random sample of purchases where the payment was made by credit card, debit card, and check, respectively. Test whether the population mean amount spent differs among the three groups, using α = 0.05. Credit Card Debit Card Check 80 100 110 90 100 120 90 110 50 70 80 80