# Question: In the hospital study cited in Exercise 19 the mean

In the hospital study cited in Exercise 19, the mean noise level in the 171 ward areas was 58.0 decibels, and the population standard deviation is 4.8. Find the 90% confidence interval of the true mean.

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

A health care professional wishes to estimate the birth weights of infants. How large a sample must be obtained if she desires to be 90% confident that the true mean is within 2 ounces of the sample mean? Assume σ = 8 ...A researcher wishes to find the confidence interval of the population standard deviation for the number of homeless people in a large city. A sample of 25 months had a standard deviation of 462. Find the 95% confidence ...U.S. insurers’ costs for knee replacement surgery range from $17,627 to $25,462. Estimate the population variance (standard deviation) in cost with 98% confidence based on a random sample of 10 persons who have had this ...In a poll of 1000 likely voters, 5 60 say that the United States spends too little on fighting hunger at home. Find a 95% confidence interval for the true proportion of voters who feel this way. In a study, 68% of 1015 adults said that they believe the Republicans favor the rich. If the margin of error was 3 percentage points, what was the confidence interval used for the proportion?Post your question