My question is in the description:)

Question

suppose that grade point average is of undergraduate students at one University a bell shaped distribution with a mean of 2.52 and a standard deviation of 0.42 using the empirical rule, what percentage of the students have grade point average is that are no more than 1.26.

Answer 1

Prob ( x  <= 1.26) =

 

Prob( z <= (1.26 - 2.52)/0.42) =

 

Prob ( z <= -3)

 

= 0.0013

 

The empirical rule states 0.3% of the data lies outside of 3 standard deviations

from the mean. For a 2 sided bell curve 0.15% = 0.015

which is consistent with the results of the probability calculation