Sodium in Breakfast Cereal. Use the following information for Exercises 78–83. A random sample of 23 breakfast cereals containing sodium had a mean sodium content per serving of 192.39 grams. Assume that the population standard deviation equals 50 grams. We are interested in whether the population mean sodium content per serving is less than 210 grams.

Question 9.189

image 83. Refer to the hypothesis test in Exercise 79. What if our level of significance equaled 0.05 instead of 0.01?

  1. Perform the appropriate hypothesis test using the -value method, but this time using level of significance .
  2. Note that your conclusion differs from that obtained using level of significance . Have the data changed? Why did your conclusion change?
  3. Suggest two alternatives for addressing the contradiction between Exercise 79 and Exercise 83(a).

9.3.83

(a) . Reject if . . . Since is , reject . There is evidence that the population mean sodium content per serving of breakfast cereal is less than 210 grams. (b) The data have not changed; was increased to a value greater than the . (c) Report the and assess the strength of the evidence against the null hypothesis; obtain more data.