Question

Find the regression​ equation, letting overhead width be the predictor​ (x) variable. Find the best predicted weight of a seal if the overhead width measured from a photograph is 2cm. Can the prediction be​ correct? What is wrong with predicting the weight in this​ case? Use a significance level of 0.05 from table = .811.

Overhead Width (cm)   7.6   8.1   9.5   8.9   9.1   7.9

Weight (kg)                  142   193   244   193   224   179

The regression equation is y (with caret) = ____ + ___x. ​(Round to one decimal place as​ needed.)

The best predicted weight for an overhead width of 2 cm is ___kg. (Round to one decimal place as​ needed.)

Answer 1

(a)

X                Y               XY               X²

7.6              142          1079.2          57.76

8.1             193             1563.3         65.61

9.5              244            2318            90.25

8.9               193            1717.7        79.21

9.1               224              2038.4       82.81

7.9               179              1414.1        62.41

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51.1          1175               10310,7     438.787

So,

The Regression equation is:

(b)

For x = 2, we get:

(c) The prediction cannot be correct.The mistake in prediction is that the x value is not within the inteval in which the data is provided.