Abdullah is a quality control expert at a factory that
paints car parts. He knows that 20% of parts have an error in their
painting. He recommended a change in the painting process, and
he wanted to see if this error rate had changed. He took a random
sample of 400 parts painted in a month and found that 60 had an
error. At 0.05 significance does the sample give evidence of
change in error rate?