While entering a concert hall, a questionnaire was given to all the members of the audience. The age of the audience was normally distributed with mean = 35 and variance = 36. What is the probability that a randomly selected spectator is:
a) Between 70 and 90 years old
b) 30 to 50 years old?
c) Less than 15 years old?
a) Between 70 and 90 years old
b) 30 to 50 years old?
c) Less than 15 years old?
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variance = 36, so SD = sqrt 36 = 6
a. z1 = (70-35)/6 = 5.83, z2 = (90-35)/6 = 9.17, P(5.83
b. z1 =(30-35)/6 = -0.83, z2 = (50-35)/6 = 2.5, P(-0.83 < z < 2.5) = 0.7905 <--------
c. z = (15-30)/6 = -2.5, P(z<-2.5) =0.0062 <---------
a. z1 = (70-35)/6 = 5.83, z2 = (90-35)/6 = 9.17, P(5.83
b. z1 =(30-35)/6 = -0.83, z2 = (50-35)/6 = 2.5, P(-0.83 < z < 2.5) = 0.7905 <--------
c. z = (15-30)/6 = -2.5, P(z<-2.5) =0.0062 <---------