People were polled on how many books they read the previous year. How many subjects are needed to estimate the number of books read the previous year within one book with 99% confidence? Initial survey results indicate that sigma equals 17.2 books.
Home
People were polled on how many books they read the previous year. How many subjects are needed to estimate the number of books read the previous year within one book with 99% confidence? Initial survey results indicate that sigma equals 17.2 books.
feel free to call us +800.241.0630 russ@russellcoder.com
Related Articles

Use the confidence interval to find the margin of error and the sample mean.
russellc, , Statistics, 0
(0.264,0.460) The margin of error is 0.098.The sample mean is .3620.


In a survey of 641 males ages 1864, 394 say they have gone to the dentist in the past year. Construct 90% and 95% confidence intervals for the population proportion. Interpret the results and compare the widths of the confidence intervals. If convenient, use technology to construct the confidence intervals. The 90% confidence interval for the population proportion p is The 95% confidence interval for the population proportion p is Interpret your results of both confidence intervals. Which interval is wider?
russellc, , Statistics, 0 
Determine whether the claim stated below represents the null hypothesis or the alternative hypothesis. If a hypothesis test is performed, how should you interpret a decision that (a) rejects the null hypothesis or (b) fails to reject the null hypothesis? A scientist claims that the mean incubation period for the eggs of a species of bird is less than 57 days.
russellc, , Statistics, 0
see excel spreadsheet. This your answer

Find the critical value tc for the confidence level c equals=0.90 and sample size n equals=18 LOADING… Click the icon to view the tdistribution table. Use a tdistribution table to look up the tvalue using the level of confidence c and the degrees of freedom nminus−1. The level of confidence c equals=0.90 is given.
russellc, , Statistics, 0 
In a random sample of 25 people, the mean commute time to work was 30.4 minutes and the standard deviation was 7.3 minutes. Assume the population is normally distributed and use a tdistribution to construct a 99 confidence interval for the population mean muμ. What is the margin of error of muμ? Interpret the results.
russellc, , Statistics, 0 
