The time it takes for a taxi to drive from the office to the airport was recorded on 40 occasions. It was found that minutes and s = 5 minutes. Give
(a) An estimate of ì = population mean time to drive.
(b)An approximate 95.4% error margin.
2 On a Thursday, students were asked to report the number of hours sleep they received the previous night. The results are summarized in the computer output
Descriptive Statistics: sleep(hrs)
Variable N Mean Median StDev SE Mean
Sleep 59 7.144 7.000 1.207 0.157
Find a 98% confidence interval for the mean number of hours sleep.
3. Computing from a large sample, one finds the 95% confidence interval for ì to be (6.8, 14.2). Based on this information alone, determine the 90% confidence interval for ì.
This solution shows how to use statistics to solve the problems given