Question

9-4 The mean pull-off force of a connector depends on cure time

1. State the null and alternative hypotheses used to demonstrate that the mean pull-off force is more than 20 newtons.
2. Assume that the previous test does not reject the null hypothesis. Does this result provide strong evidence that the mean pull-off force is less than or equal to 20 newtons?
3. Assume that the previous rejects the null hypothesis. Does this result provide strong evidence that the mean pull-off force is more than 20 newtons?

Answer 1

a) null and alternative hypotheses.

Null hypothesis H_{​​​​​​0} :    20  

Alternative hypothesis H_​1 :   > 20

b) our test does not reject the null hypothesis , so we conclude that the result provide strong evidence that mean pull of force is less than or equal to 20 Newtons . This is correct conclusion.

c) now we reject the null hypothesis , so we conclude that there is strong evidence that mean pull-off force is more than 20 newtons . This is also correct .