confidence interval for a mean

What is meant by 95% confidence interval of the mean? => 95% of the specific sample means will fall within ± 1.96 standard errors of the population mean. or 95% of the specific sample means will fall within ± 2.58 standard er..

A random sample of 86 days taken at a large hospital shows that an average of 32 patients were treated per day. The 95% confidence interval of the mean number of patients treated each day at the hospital is between 30 and 34. Find the 95% confidence inte..

95% confidence interval of a population mean worked out on a sample size of 10 is, 0.26 < μ < 0.38. What is the likely 95% confidence interval of the mean of the same population worked out on a sample size of 20? => 0.28 < μ..

The 95% confidence interval for the mean number of tablets in a bottle of calcium tablets is between 149.04 and 150.96. The standard deviation is 3 tablets. Find the size of the random sample that was used to determine this interval. => 40 or 38 or 6 or 150 o..

The 95% confidence interval for the mean weight of a sack of potatoes is between 4.92 and 5.08. If a random sample of 32 sacks was used to determine this interval, what was the standard deviation? => 0.04 or 0.16 or 3.92 or 0.23..

The number of miles per hour driven by a sales person on 14 different days is listed here. What is the point estimate for the mean? Find the 95% confidence interval of the mean for the average miles per hour. => 32.3 and 29.5 < μ < 35.1 or 31.5 and 3..

When should the t distribution be used to find a confidence interval for the mean? => When the sample size of population is greater than 30 and the standard deviation is known. or When the sample size of population is less than 30 and the standard deviation is known. o..

A sample of the reading scores of 35 sixth graders has a mean of 82. If the 95% confidence interval for the population mean of the reading scores of all fifth graders is between 77 and 87, then which among the following choices represents the 99% confide..

A survey of software engineers having more than ten years experience finds the average salary to be $120,000. If the standard deviation for the sample of 40 software engineers was $12,000, construct a 99% confidence interval of the mean(μ) for all engineers. => 118,..

The number of ATM transactions of a bank per day were recorded at 12 locations in a city. The mean of the sample was 88.5 transactions, with a sample standard deviation of 42. Find the 98% confidence interval of the true mean. => 19.06 < μ < 157.94 o..