Given μ=70.5 and σ=4.6 of normal distribution, find
а. p(65 < х < 75)
b. p(72 < x < 80)
c. p(x > 80)
d. p(x < 65)
a)
for normal distribution z score =(X-μ)/σx | |
here mean= μ= | 70.5 |
std deviation =σ= | 4.6000 |
probability = |
P(65
= |
P(-1.2 |
0.8365-0.1151= |
0.7214 |
|
b)
probability = |
P(72
= |
P(0.33 |
0.9808-0.6293= |
0.3515 |
|
c)
probability = | P(X>80) | = | P(Z>2.065)= | 1-P(Z<2.07)= | 1-0.9808= | 0.0192 |
d)
probability = | P(X<65) | = | P(Z<-1.2)= | 0.1151 |
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