SOLUTION: I have zero idea what this question is asking me and could really use some help. Please and thank you. Given x is a normal variable with mean u=110 and standard deviation o=12 fin

Algebra ->  Probability-and-statistics -> SOLUTION: I have zero idea what this question is asking me and could really use some help. Please and thank you. Given x is a normal variable with mean u=110 and standard deviation o=12 fin      Log On


   

Question 750226: I have zero idea what this question is asking me and could really use some help. Please and thank you.
Given x is a normal variable with mean u=110 and standard deviation o=12 find
A. P(x≤120)
B. P(x≥ 80)
C. P( 108≤ x≤ 117)
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Given x is a normal variable with mean u=110 and standard deviation o=12 find
A. P(x≤120)
z(120) = (120-110)/12 = 10/12 = 5/6
P(x <= 120) = P(z < 5/6) = normalcdf(-100,5/6) = 0.7977
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B. P(x≥ 80)
z(80) = (80-110)/12 = -30/12 = -5/2
P(x >= 80) = P(z >= -5/2) = normalcdf(-5/2,100) = 0.9938
--------------------------
C. P( 108≤ x≤ 117)
Find the z-value of 108 and of 117
Find the probabilility that z lies between those z values:
P(108<= x <=117) = 0.2863
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Cheers,
Stan H.
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