Question

# The extract of a plant native to Taiwan has been tested as a possible treatment for...

The extract of a plant native to Taiwan has been tested as a possible treatment for Leukemia. One of the chemical compounds produced from the plant was analyzed for a particular collagen. The collagen amount was found to be normally distributed with a mean of 7171 and standard deviation of 9.99.9 grams per mililiter.

1.   What percentage of compounds formed from the extract of this plant fall within 22 standard deviations of the mean?

Given that the collagen amount was found to be normally distributed with a mean of = 71 and the standard deviation of = 9.9 grams per mililiter.

1. to calculate the probability between 2 standard deviations of a normal distribution the empirical rule can be sufficient. The empirical rule state that 95% of data lies within 2 standard deviations of the mean.

or, we could use the excel formula for normal distribution which is =NORM.S.DIST(2,TRUE)-NORM.S.DIST(-2,TRUE), this results in proportion = 0.9545. we convert into a percentage we get 95.45 %.

Note : You may use both but the excel formula is very much accurate value, so choose according to the question.