I need to know how to calculate the distribution of a total based on taking 20 samples from a normal distribution and toitalling them. How much will the total vary? Can I calculate the percentiles for this?
Here is an example:
What is the 90 percentile range for 20 work items with an average cost of £10k with a standard deviation of £4k?
Assuming a normal distribution is reasonable.
The 90th percentile for a single story works out to be between £3.4k and £16.6k (which is quite a big range)
The average cost of all 20 work items would be £200k.
The 90th percentile for all 20 stories is between £X and £Y.
How do I calculate £X and £Y?
Here is an example:
What is the 90 percentile range for 20 work items with an average cost of £10k with a standard deviation of £4k?
Assuming a normal distribution is reasonable.
The 90th percentile for a single story works out to be between £3.4k and £16.6k (which is quite a big range)
The average cost of all 20 work items would be £200k.
The 90th percentile for all 20 stories is between £X and £Y.
How do I calculate £X and £Y?
