change those masses in each section to standard deviations, and ...
http://onlinestatbook.com/2/calculators/normal_dist.html
The Empirical Rule: The weight,in the grams, of the pair of kidneys in adult males the ages of 40 and 49 has a bell-shaped distribution with a mean of 325 grams and a standard deviation of 30 grams.
A) About 95% of kidney pairs will be between what weights?
B)What percentage of kidney pairs weighs less between 235 grams and 415 gram?
C) What percentage of kidney pairs weighs less than 235 grams or more than 415 grams?
D) What percentage of kidney pairs weighs between 295 grams and 385 grams?
3 answers
and here is a better one
https://homepage.divms.uiowa.edu/~mbognar/applets/normal.html
https://homepage.divms.uiowa.edu/~mbognar/applets/normal.html
I am sorry not trying to take up your time can you please help me understand the problem