1)CNNBC recently reported that the mean annual cost of auto insurance is 1043 dollars. Assume the standard deviation is 269 dollars. You take a simple random sample of 67 auto insurance policies.

Find the probability that a single randomly selected value is less than 984 dollars.

P(X< 984) =

Find the probability that a sample of sizen=67n=67is randomly selected with a mean less than 984 dollars.

P(M< 984) =

Enter your answers as numbers accurate to 4 decimal places.

2)If n=450 and p' (p-prime) = 0.48, construct a 90% confidence interval.

Give your answers to three decimals.

< p <

3)In a survey, 24 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $46 and standard deviation of $12. Construct a confidence interval at a 90% confidence level.

Give your answers to one decimal place.

4)You measure 47 textbooks' weights, and find they have a mean weight of 64 ounces. Assume the population standard deviation is 6.3 ounces. Based on this, construct a 95% confidence interval for the true population mean textbook weight.

Give your answers as decimals, to two places

<<