what\'s the answer from 3-7 SHORT ANSWER. Write the word or phrase that best com
ID: 3041262 • Letter: W
Question
what's the answer from 3-7
SHORT ANSWER. Write the word or phrase that best completes each statement or a 3) The numbers of advertisements seen or heard in one week for 30 random nswers the question. in the United States are listed below. Construct a 95% confidence people 3) interval for the true mean number of advertisements 598 494 441 595 728 690 84 486 735 808 481 298 135 846 764 317 649 732 582 677 734 588 540 673 727 45 486 702 703 MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 4) In order to fairly set flat rates for auto mechanics, a shop foreman needs to estimate the average time it takes to replace a fuel pump in a car. How large a sample must he select if he wants to be 99% confident that the true average time is within 15 minutes of the sample average? Assume the standard deviation of all times is 30 minutes A) 6 26 Find the indicated critical z value 5) Find the critical value za/2 that corresponds to a 98% confidence level B) 1.75 A) 2.575 C) 2.33 D) 205 6) Find the critical value za/2 that corresponds to a 94% confidence evel B) 2.75 A) 1.88 C) 1.96 D) 1.555 Provide an appropriate response 7) Construct a 95% confidence interval for the population mean, Assume the population has a normal distribution. A random sample of 16 fluorescent light bulbs has a mean life of 645 hours with a standard deviation of 31 hours B) (876.2, 981.5) C) (531.2, 612.9) D) (628 5,661.5) A) (321.7, 365.8)Explanation / Answer
3.
Please post 1 question per post. Write back in case you have doubts.
The Z value for 99% confidence is 2.56.
99% confident wiht 15 minutes of average. Stdev = 30 min
So, Margin of error <= Z*sigma/sqrt(n)
Reshuffling, and therefore signs will change:
15 > 2.56*30/sqrt(n)
n>(2.56*30/15)^2
n>26.21,
therefore n = 27
D. is correct
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.