Help me with this problem please

Question

3. For a given population, the mean is 45 and the standard deviation is 4.1
a) Draw the Normal model for distribution to the right. Put the appropriate values on x-axis to 3 standard deviations on each side of mean.
b) How many standard deviations away from the mean is 42?
c) What percentage of values are below 48?
d) If the population contains 120 values, how many values are above 48?

Answer 1

b)      (42-45)/4.1 = -3/4.1 = -0.73107

 

C)  Prob ( z < (48-45)/4.1) = Prob (z < 0.73107)=0.73565 = 73.565%

 

d)  120 * (100% - 73.565%) = 31.722 ---> 31 or 32 of them