continuous random variables

#1
how would i compute the answer to the following question:

Scores on a particular test are normally distributed in the population with a mean of 100 and a standard deviation of 15. What percentage of the population have scores...

a) between 100 and 125 [ANS: 45.25]
b) above 132 [ANS: 1.66]
c) equal to 132 [ANS: 0]
 
E

elnaz

Guest
#2
Hello
to take notice table of normal:
1) p((100-100)/15 <z<(125-100)/15)~.4525 => *100=45.25
2)p(z>(132-100)/15)=1-p(z<(132-100)/15)=.12=> *100=12
3) becouse z is continuous random variables then p(z=(132-100)/15)=0