Listed below are speeds​ (mi/h) measured from traffic on a busy highway. This simple random sample was obtained at​ 3:30 P.M. on a weekday. Use the sample data to construct a 90​% confidence interval estimate of the population standard deviation. 65,64,64,56,64,53,61,60,61,68,60,66       Click the icon to view the table of​ Chi-Square critical values The confidence interval estimate is __mi/h<σ<__mi/h.

One year, the mean age of an inmate on death row was 40.5 years. A sociologist wondered whether the mean age of a death-row inmate has changed since then. She randomly selects 32 death-row inmates and finds that their mean age is 39.4, with a standard deviation of 9.5. Construct a 95% confidence interval about the mean age. What does the interval imply? Question Help v E Click the icon to view the table of critical t-values. Choose the correct hypotheses. Ho: O Table of Critical t-Values %3D H: (Type integers or decimals. Do not round.) Area in vight tail -Distribution Area in Right Tail Degrees of Freedom 0.25 0.20 0.15 0.10 0.05 0.025 0.02 001 0.005 0.0025 0.001 0.0005 1.000 1.376 1.061 0.978 0.941 0.920 1.963 1.386 1.250 1190 1.156 3.078 1886 1638 1.533 1476 6.314 12.706 15.894 4849 3.482 2.999 2.757 2.612 2.517 2.449 2.398 2.359 2.328 2.303 2282 2.264 2.249 31821 63657 6.965 4.541 3.747 3.365 127321 318.309 636.619 22.327 10.215 Z173 5.893 5.208 4.785 4.501 4.297 4.144 2 0816 0.765…

Sales personnel for Skillings Distributors submit weekly reports listing the customer contacts made during the week. A sample of 85 weekly reports showed a sample mean of  17.5 customer contacts per week. The sample standard deviation was 5.4 . Provide  90 % and  95 % confidence intervals for the population mean number of weekly customer contacts for the sales personnel. 90% confidence interval, to 2 decimals: ( ,  ) 95% confidence interval, to 2 decimals: ( , )

A sample of 106 body temperatures was taken and the mean was 98.2 degrees F. The population standard deviation is 0.62 degrees.  Use a 0.05 level of significance to test the claim that the average body temperature is actually different than 98.6 degrees F.  Find the 95% confidence interval of the mean temperature and compare your results.

We want to estimate the true mean number of ounces of water a high school athlete drinks each day at a 95% confidence level. A random sample of 15 athletes from a school is selected and their typical daily water consumption is reported below: 64, 72, 80, 88, 128, 128, 128, 132, 145, 155, 160, 175, 180, 200, 225 What is the value of the standard error of the mean? (When calculating, use the standard deviation of the sample rounded to 3 decimal places and then round your standard error answer to 3 decimal places.)   =

Sales personnel for Skilling Distributors submit weekly reports listing the customer contacts made during the week. A sample of 15 weekly reports showed a sample mean of 19.5 customer contacts per week. The sample standard deviation was 5.2. Provide a 90% confidence interval for the population mean number of weekly customer contacts for the sales personnel.

Yane is a researcher who studies bacteria. They are trying to ascertain the mean lifespan for a bacteria species. It is believed that the standard deviation of their lifespan is o = 4 hours. They would like to estimate the mean lifespan for this species of bacteria to within a margin of error of 0.45 hours at a 99% level of confidence. What sample size should they gather to achieve this? Remember your answer must be a whole number. n= bacteria

Salaries of 34 college graduates who took a statistics course in college have a mean, x, of $67,400. Assuming a standard deviation, o, of $15,845, construct a 90% confidence interval for estimating the population mean u.

A sample of 100 postal employees found that the mean time these employees had worked for the postal service was eight years. Assume we know the standard deviation of the population of times postal service employees have spent with the postal service is five years. Find the 98% confidence interval for the mean time the population of postal service employees have spent with the postal service.

One year, the mean age of an inmate on death row was 38.1 years. A sociologist wondered whether the mean age of a death-row inmate has changed since then. She randomly selects 32 death-row inmates and finds that their mean age is 36.9, with a standard deviation of 9.8. Construct a 95% confidence interval about the mean age. What does the interval imply? A Click the icon to view the table of critical t-values. Choose the correct hypotheses. Но (Type integers or decimals. Do not round.)