Question 1079760
a.  z-score = (8 - 8.4) / 0.16 = −2.5
lookup z-score in normal distribution z-tables
Probability ( X < 8 ) = 0.0062
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b.  Probability ( X > or = 8.5 ) = 1 - Probability ( X < 8.5 )
z-score = (8.5 - 8.4) / 0.16 = 0.625
Probability ( X < 8.5 ) = 0.73401
Probability ( X > or = 8.5 ) = 1 - 0.73401 = 0.266
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