A computer chip manufacturing company finds that 10% 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 240 chips revealed only 21 defects.

Perform an appropriate hypothesis test to determine whether this sample provides statistically significant evidence (at the= 5% level)that the defective rate is now lower.

Assume all necessary conditions have been met.