Question

Using the simple random sample of weights of women from a data​ set, we obtain these sample​ statistics: n=45 and x over bar equals=146.55 lb. Research from other sources suggests that the population of weights of women has a standard deviation given by sigma = 30.64lb.

a. Find the best point estimate of the mean weight of all women.

b. Find a 90​% confidence interval estimate of the mean weight of all women.

a. The best point estimate is _____lb. ​(Type an integer or a​ decimal.)

b. The 90​% confidence interval estimate is lb less than<muμless than<nothing lb. ​(Round to two decimal places as​ needed.)

Answer 1

a)

Best point estimate of mean = ​​​​​​ = 146.55 lb

b)

90% confidence interval for is

- z * / sqrt(n) < < + z * / sqrt(n)

146.55 - 1.645 * 30.64 / sqrt(45) < < 146.55 + 1.645 * 30.64 / sqrt(45)

139.04 < < 154.06

139.04 lb < < 154.06 lb