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)

Answer 1

To find the time within which you will complete the project with a 90% confidence level, you can use the z-score formula. Substitute the relevant values into the formula to calculate the time.

Step-by-step explanation:

To find the time within which you will complete the project with a 90% confidence level, you need to calculate the z-score corresponding to a 90% confidence level. Since you have the standard deviation of the critical path, you can use the z-score formula: z = (x - mean) / standard deviation. Rearranging the formula, we get x = (z * standard deviation) + mean. Substitute the z-score for a 90% confidence level (1.645), the standard deviation of 10 days, and the mean of 40 days into the formula to find the time with 90% confidence can be calculated as follows:

x = (1.645 * 10) + 40 = 16.45 + 40 = 56.45

Rounding to the nearest whole number, the time within which you will complete the project with 90% confidence level is 56 days.

Answer 2

The answer is "53 days"

Step-by-step explanation:

The form for the due date is given below from the above information.

`\text{DUE DATE = Expected Completion Time} + (Z * \text{Standard Deviation)}`

The level of confidence relates to the percentage of all samples which can contain a true population variable. It is calculated by a random sampling of the population and is often linked with a certain level of confidence, which would be a probability, usually a percent. The 90% say that the true mean will be 90%, but 10% won't.

The Z-score needs to be measured, measured from percentage points away from the mean in statistics of a value related to the mean (which is to say, the average) of one sequence of items.

`Expected\ time = 40 \\\\Confidence \ interval = 90 = Z-VALUE \ of\ 1.282\\\\Standard \ Deviation= 10\\\\DUE \ DATE = 40 + (1.282 * 10) = 53 \ days\\\\= 40+ 12.82 =52.82 \approx 53\\\\\therefore`

The time in days is 53 days.