For Exercises 15–24, use the data and the regression equations that you calculated in the Section 13.1 exercises.
21. World Temperatures. Refer to the data from Exercise 17.
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13.2.21
(a) Lower bound: 22.1568 degrees (Minitab: 22.1564); Upper bound: 64.5317 degrees (Minitab: 64.5322) (b) The range of the low temperatures in the data set is from 7°C to 70°C, inclusive. Therefore, a low temperature of 0°C is outside of the range of our data set, and any predictions or estimates using the regression equation for 0°C represent extrapolation. Extrapolation should be avoided if possible because the relationship between the variables may no longer be linear outside the range of .