Wrinkle recovery angle and tensile strength are the two most

Wrinkle recovery angle and tensile strength are the two most important characteristics for evaluating the performance of crosslinked cotton fabric. An increase in the degree of crosslinking, as determined by ester carboxyl band absorbance, improves the wrinkle resistance of the fabric (at the expense of reducing mechanical strength). The accompanying data on x = absorbance and y = wrinkle resistance angle was read from a graph in the paper \"Predicting the Performance of Durable Press Finished Cotton Fabric with Infrared Spectroscopy\".†

Here is regression output from Minitab:

7756.0

Solution

b)

The regression equation using the output can be written as -

Y = 321.878 + 156.711 (X)

Where Y is the Wrinkle resistant angle and X is the absorbance value.

So, for X = 0.250, the predicted value of Y using the regression model is -

Y = 321.878 + 156.711 (0.25) = 361.05575

So, the predicted wrinkle resistant angle = 361.06

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c)

The expected value of the wrinkle resistant angle would be same as earlier because the mean of the samples will be same as the population mean.

So, the expected value of wrinkle resistant angle = 361.056