Statistics suggest that software developers with two years of experience in Ontario earn an average of 70,000 per year, with a standard deviation of 5,000. To verify this salary level, a random sample of 100 software developers with two years of experience was selected from a personnel database for all software developers in Ontario.
- (a) Describe the sampling distribution of the sample mean X ̄ of the average salary of these 100 Software Developer.
- (b) Calculate the probability that X is greater than or equal to 71,200.
- (c) If the random sample actually produced a sample mean of 71,200, would you consider this rather unusual? What conclusion might you draw then?
