Question 487044
Use the formula z = (X - M)/s.d
a) z = (115 - 100)/15 = 15/15 = 1
b) P ( 100 < X < 115) = P((100 - 100)/15 <z < (115 -100)/15) = P(0 <z < 1) = 0.341 or 34.1%
c) Draw a picture and use 68%-95%-99.5% rule to find about 34% of the students who score 115.