# Question: Find the 90 confidence interval for the variance and standard

Find the 90% confidence interval for the variance and standard deviation for the lifetimes of inexpensive wristwatches if a sample of 24 watches has a standard deviation of 4.8 months. Assume the variable is normally distributed. Do you feel that the lifetimes are relatively consistent?

**View Solution:**## Answer to relevant Questions

The number of carbohydrates (in grams) per 8-ounce serving of yogurt for each of a random selection of brands is listed below. Estimate the true population variance and standard deviation for the number of carbohydrates per ...In each case, find an . a. n = 80 and X = 40 b. n = 200 and X = 90 c. n = 130 and X = 60 d. n = 60 and X = 35 e. n = 95 and X = 43 A recent study indicated that 29% of the 100 women over age 55 in the study were widows. a. How large a sample must you take to be 90% confident that the estimate is within 0.05 of the true proportion of women over age 55 ...A U.S. Travel Data Center survey conducted for Better Homes and Gardens of 1500 adults found that 39% said that they would take more vacations this year than last year. Find the 95% confidence interval for the true ...A recent study of 28 employees of XYZ company showed that the mean of the distance they traveled to work was 14.3 miles. The standard deviation of the sample mean was 2 miles. Find the 95% confidence interval of the true ...Post your question