Please answer A, B, and D variant.
The manufacturer of a travel alarm clock claims that, on the average, its clocks deviate from perfect time by 30 seconds per month, with a standard deviation of 10 seconds. Engineers from a consumer magazine purchase 40 of the clocks and find that the average clock in the sample deviated from perfect accuracy by 34 seconds in one month.
- What is the point estimate of the population mean?
- What is the point estimate of the population standard deviation?
- If the manufacturer's claim is correct (i.e., 30 seconds, 10 seconds), what is the probability that the average deviation from perfect accuracy would be 34 seconds or more?
- Based on your answer to part (a), speculate on the possibility that the manufacturer's claim might not be correct?