Question

You have just used the network planning model for a county road resurfacing project and found the critical path length is 40 days and the standard deviation of the critical path is 10 days. Suppose you want to pick a time (in days) within which you will complete the project with 90% confidence level, what should be that time (in days and round to the nearest whole number.)
A. 40B. 13C. 45D. 29E. 53

Answer 1

Answer: E.53

Explanation:

From the above information, the formula for due date is given below.

DUE DATE = Expected Completion Time + (Z * Standard Deviation)

A confidence level refers to the percentage of all possible samples that can be expected to contain the true population parameter. It is computed according to a random sample from the population and most times always associated with a certain confidence level that is a probability, usually presented as a percentage. The 90% says that 90% will include the true mean but 10% won't.

A Z-score is referred to as a numerical measurement that is made use of in statistics of a value's relationship to the mean (that is average) of a group of values, measured in terms of standard deviations away from the mean.

Expected time = 40

Confidence interval = 90 = Z VALUE of 1.282

Standard Deviation= 10

DUE DATE = 40 + (1.282 * 10) = 53days

= 40+ 12.82

=52.82

Approximately 53

Therefore,the time in days is 53 days.

Answer 2

Answer:

E- 53

Explanation:

FORMULA:

DUE DATE = EXPECTED COMPLETION TIME + (Z * STDEV)

Expected time = 40

CONFIDENCE INTERVAL = 90 = Z VALUE OF 1.282

STANDARD DEVIATION = 10

DUE DATE = 40 + (1.282 * 10) = 53