The average time a student spends studying just prior to a test is 36 minutes with a standard deviation of 5 minutes. This distribution approximates a normal curve. Find the percent of students who study just prior to the test for. a) more than 40 minutes b) between 35 and 45 minutes

Question

The average time a student spends studying just prior to a test is 36 minutes with a standard deviation of 5 minutes. This distribution approximates a normal curve. Find the percent of students who study just prior to the test for. a) more than 40 minutes    b) between 35 and 45 minutes

Brandon · Answer

ncdf(40,1000,36,5)=.212 a)
ncdf(35,45,36,5)=.543 b)

its been a while so im not 100% sure if its right but i think it is :)

dont forget to draw the normal curves on your assignment my teachers alwyas made me haha

PsyDAG · Answer

Z = (score-mean)/SD

Calculate the various Z scores.

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions related to these Z scores