Table A2
-For this question,please use the standard normal distribution table,Table A2.It has been estimated that the mean time required to complete a project is 20 weeks and the variance of project completion time is 9 weeks.So there is a 95% chance that the project can be completed in
A)10 weeks.
B)19 weeks.
C)20 weeks.
D)26 weeks.

Question

Table A2
-For this question,please use the standard normal distribution table,Table A2.It has been estimated that the mean time required to complete a project is 20 weeks and the variance of project completion time is 9 weeks.So there is a 95% chance that the project can be completed in
A)10 weeks. 
B)19 weeks. 
C)20 weeks. 
D)26 weeks.

Quizplus · Accepted Answer

To find the time within which there is a 95% chance of project completion, we use the standard normal distribution. With a mean ($\mu$) of 20 weeks and a variance ($\sigma^2$) of 9 weeks, the standard deviation ($\sigma$) is $\sqrt{9} = 3$ weeks. A 95% chance corresponds to a Z-score of approximately 1.96 (from the standard normal distribution table for 95% in the middle). Using the formula $X = \mu + Z\sigma$, we get $X = 20 + 1.96(3) = 25.88$, which rounds to 26 weeks.

Table A2 -For This Question,please Use the Standard Normal Distribution Table,Table A2.It