Patrick B. answered 10/21/20
Math and computer tutor/teacher
Thank you Ms. Darlene!!!!
Prob ( x < 68) =
Prob ( z < (68-67.3)/4 ) = <-- changes to z-score
Prob ( z < 0.175) =
0.56946 <--- per the Normal Bell Curve table
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Prob ( 68 < x < 70) =
Prob( x < 70) - Prob(x<68) =
Prob( z < (70-67.3)/4) - Prob(x < 68) =
Prob( z < 0.675) - Prob(z < 0.175) =
0.750162 - 0.56946 = 0.180702
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Prob(z > 70) =
1 - Prob(z<70) =
1 - 0.750162 =
0.249838 < 25%