Question 1050443
a) P(X > 0.64) = 1 - P(X < 0.64)
:
z-score = (0.64 - 0.5) / 0.05 = 2.8
:
consult z-tables for associated probability
:
P(X < 0.64) = 0.9974
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P(X > 0.64) = 1 - 0.9974 = 0.0026
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b) P(X > 0.47 and X < 0.65) = P(X<0.65) - P(X < 0.47)
:
z-score = (0.65 - 0.5) / 0.05 = 3
:
z-score = (0.47 - 0.5) / 0.05 = -0.6
:
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P(X > 0.47 and X < 0.65) = 0.9987 - 0.2743 = 0.7244
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