Question

For a recent 10k run the finishers are normally distributed with mean 62 minutes and standard deviation 11 minutes.
Approximately ?% finished in less than 80 mins?

Answer 1

and ..... whats the question?

Answer 2

what is the percent that finished in less than 80 minutes

Answer 3

ok, and what are your thoughts on how to proceed?

Answer 4

do you have ot use a table or a calculator like a ti83?

Answer 5

I don't know where to begin and yes i have the calculator

Answer 6

is the calculator a ti83 or similar?

Answer 7

if so, press 2nd, VARS to enter the stats distribution menu

choose the normalCDF function and enter in the parameters: (low, high, mean, sd)

http://www.wolframalpha.com/input/?i=normalcdf%28-9999%2C80%2C62%2C11%29

Answer 8

otherwise, if by tables you need to determine a zscore to look up

Answer 9

ti83

Answer 10

ti83 is what i learned on ... 2nd, VARS normalCDF will do fine

Answer 11

if you want to know why we use that function, it tells us the cumulative probability of a normal distribution between endpoints, with a stated mean and standard devaition.

Answer 12

what do i type when i get past normalCDF

Answer 13

you enter in 4 parameters: low, high, mean, sd these values are stated in the problem

well, the low is implied as -infinity but i just use a 'big' negative number to accomodate it

Answer 14

http://www.wolframalpha.com/input/?i=normalcdf%28-9999%2C80%2C62%2C11%29