Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

The 2008 Workplace Productivity Survey, commissioned by LexisNexis and prepared

ID: 3056991 • Letter: T

Question

The 2008 Workplace Productivity Survey, commissioned by LexisNexis and prepared by worldOne REsearch included the question, "How many hours do you work at your job on a typical workday" Let x= # of hours a legal proffessional works on a typical workday. Suppose x is normally distributed with a known standard deviation of 11.9. A sample of 250 professionals was surveyed, and sample means response was 9 hours. The sampling distribution of X*with a line over the X* Is normal with a mean of ____ and a standard deviation of_____. You can be 95% confident that the interval estimate ____ to ____ includes population mean.

Also this is second part of question. please please answer both because I already used one of my questions asking it but i got the wrong answer so I have to reask the same one.

The business Environemtn and Enterprise PEformance Survey developed by European bank is a survey with 4000 firms in 22 transition countries. For the sample of 46 exporting firms in turkey, the sample mean was 2.8 days and the standard deviation was 3.4 days. To develop a 90% confidence interval estimate of the mean number of days it takes for exported goods to be released in Turkey, use the __________/ You are 90% confident that the mean wait time for exported goods to be released in turkey is between ___ and ___ days. The confidence itnerval estimate you calculated is appropriate because a) you are assuming population distribution is not highly skewed nor contains outliers and sample size is at least 30. b) the wait time for exported goods to be released in turkey is normally distributed c) using the t distribution means sampling distribution of mean does not need to be normal.

C courses.cpl .com af servet, quiz?quiz_action-take uz&quiz;, rob id-ONAPC A 01010000003c5dabe0050000 ict kathleen. ili m 00208 c 1 1612DEA462617D80C00 2. Interval estimatiun fa population mean, population standard deviation unnown in ano, tsess .thirid nitrrrahan nn t rth in br nccun take from the timeyou sunmit your :ocdt urbi tre time they 3rerseMed?" For the 53male or 46 exprt ng fhmsin TS ceselo g0% condence irtere21 estimate cr the mean numbe, oc caps it taos fer exported goods to be Distributions The canidene imeval estimate you calcu td &ppropnst; tecaus: t least 30.

Explanation / Answer

1)

s = 11.9 , mean = 9 , n = 250

The sampling distribution of X*with a line over the X* Is normal with a mean of 9

standard deviation = s/sqrt(n)
= 11.9/sqrt(250)
= 1.6829

z value at 95% = 1.96

CI = mean + /- z * ( s/sqrt(n))
= 9 +/- 1.96 * 1.6829
= (5.7015 , 12.2985)
95% confident that the interval estimate 5.7015 to 12.2985 includes population mean.

2)

To develop a 90% confidence interval estimate of the mean number of days it takes for exported goods to be released in Turkey, use the t value = 1.6794

mean = 2.8 , s = 3.4 , n = 46

t value at 90% = 1.6794

CI = mean + /- t * ( s/sqrt(n))
= 2.8 +/- 1.6794 * (3.4/sqrt(46))
= (1.9754 , 3.6246)
90% confident that the mean wait time for exported goods to be released in turkey is between 1.9581 and 3.6418 days