2. X is a normally distributed variable with mean µ = 30 and standard deviation
? = 4. Find
a) P(x < 40)
(Ans 0.9938)
b) P(x > 21)
(Ans 0.9878)
c) P(30 < x < 35)
(Ans 0.3944)
3. The mean height of 200 students is 1,70 m with a standard deviation of 0,06
m. Determine how many students are:
3.1 taller than 1,65m (Ans 159)
3.2 between 1,74m and 1,82m (Ans 46)
3.3 shorter than 1,65m. (Ans 41)
4. The average time required to perform a medical procedure is 78,5 minutes with a
standard deviation of 6,25 minutes. Determine the probability that a job can be done
anytime from 70 to 80 minutes. (Ans 0.5079)