Central Limit Theorem

Question

Hi!

I have all of the other parts of this question finished, but I am having trouble on this one.

For the 39 cities, find the probability that the average amount of pollutants is less than 7.8 ppm. 

Using Excel NORM.DIST

X=7.8

mean= 8.6

Standard Deviation= 0.2082

Cumulative= 1

I keep getting but I know it isn't supposed to be a whole number.

Any help or advice would be appreciated!

Answer 1

means 6.09 times 10^-5 which is not a whole number (in fact it is very close to 0 meaning your probability is tiny). Your value is correct so good job!