Question

According to a recent study annual per capita consumption of milk in the United States is 22.6 gallons. Being from the Midwest, you believe milk consumption is higher there and wish to test your hypothesis. A sample of 14 individuals from the Midwestern town of Webster City was selected and then each person's milk consumption was entered into the Microsoft Excel Online file below. Use the data to set up your spreadsheet and test your hypothesis. Gallons of Milk 29.6 23.84 25.25 21 17.52 19.61 19.83 26.18 34.97 30 28.59 20.57 26.94 27.24 a. Develop a hypothesis test that can be used to determine whether the mean annual consumption in Webster City is higher than the national mean. b. What is a point estimate of the difference between mean annual consumption in Webster City and the national mean? c. At a=.05, test for a significant difference. What is your conclusion?

Answer 1

= 25.08

s = 4.94

a) H₀: = 22.6

    H₁: > 22.6

b) - = 25.08 - 22.6 = 2.48

c) The test statistic t = ( - )/(s/)

                                 = (25.08 - 22.6)/(4.94/)

                                 = 1.878

At = 0.05, the critical value is t_{0.95, 13} = 1.771

As the test statistic value is greater than the critical value (1.878 > 1.771), we should reject the null hypothesis.

So there is sufficient evidence to support the claim that the mean annual consumption in Webster city is higher than the national mean.