Question

Data are drawn from a symmetric and bell shaped distribution with a mean of 120 and a standard deviation of 5. There are 900 observations in the data set. What percentage of observations are less than 130? How many observations are less than 130? This is suppose to be two different questions but they seem the same to me. Please please please help me.

Answer 1

How many requests an actual number, not a percent. To get the number from the percentage, assume you've got p% observations (which is 97.5%). The actual number of observations is p*900/100, that is 9 times the 97.5% or 877.5 observations (I know, odd thing you get a non-integer). I guess I got the wrong percentage (I don't do statistics just yet at school ;) )