Question 7.120

7.120 Recovery from wrinkles.

Of course, the reason for durable press treatment is to reduce wrinkling. “Wrinkle recovery angle’’ measures how well a fabric recovers from wrinkles. Higher is better. Here are data on the wrinkle recovery angle (in degrees) for the same fabric specimens discussed in the previous two exercises:

wrinkle

Permafresh 55 136 135 132 137 134
Hylite LF 143 141 146 141 145

Which process has better wrinkle resistance? Is the difference statistically significant?