A sample of 25 blue-collar employees at production plant was taken. Each and every employee was asked to assess his own job satisfaction (x) on scale from 1 to 10. In addition, the numbers of days absent (y) from work throughout the last year were found for these employees. The sample regression line yi=11.6-1.2x was estimated by least squares for such data.

Also found were:

sample mean = 6

Sum of (x-xmean)2=130

SSE= 80.6

a) Test at the 1% significance level against the appropriate one-sided alternative null hypothesis that job satisfaction has no linear effect on absenteeism.

b) A particular employee has job satisfaction level 4. Find a 90% interval for the number of days this employee would be absent from work in a year.