The production manager wants to compare the number of defective wheelchairs produced on the day shifts with the number on the afternoon shift. A sample of the production from 6 day shifts and 8 afternoon shifts revealed the following number of defects.
Day 5 8 7 6 9 7
Afternoon 8 10 7 11 9 12 14
At 0.05 significance level, is there a difference in the mean number of defects per shift? Assume that the populations are approximately normally distributed and the variances are equal.