A company manufacturing computer chips finds that 8% of all chips manufactured are defective. In an effort to decrease the percentage of defective chips, management decides
To provide additional training to those employees hired within the last year. After
Training was implemented, a sample of 450 chips revealed only 27 defects. A hypothesis
Test is performed to determine if the additional training was effective in lowering the
Defect rate. Which of the following statement is true about this hypothesis test?
A) It is a two tailed test about a proportion.
B) It is a one tailed test about a mean.
C) It is a one tailed test about a proportion.
D) It is a two tailed test about a mean.
E) None of the above.

Question

Quizplus · Accepted Answer

Since we are testing whether the training has reduced the percentage of defective chips, it is a one-tailed test about a proportion (the proportion of defective chips). We want to see if the proportion has decreased after the training, so we are only interested in the left-tail of the distribution.

A Company Manufacturing Computer Chips Finds That 8% of All