Question 925688
mean = 55, SD = 13 , n = 25  z ={{{blue (x - 55)/blue(13/sqrt(25))}}}
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Using the z-value to determine the Probability:
P(x > 59) = P(z > 4/2.6) = P(z > 1.54) = 1 - P(z < 1.54) = .0618
 Using a TI calculator 0r similarly a Casio fx-115 ES plus
P(z > 1.54) = normalcdf(1.54,100) = .0618
.............
P(x < 51) = P( z < -4/2.6) = P( z < -1.54) = normalcdf(-100, 1.54) =  .0618
......
P(51 < x < 59) = P( -1.54 < z < 1.54) =  1 - .0618 - .0618 = .8764
Or
 Using a TI calculator 0r similarly a Casio fx-115 ES plus
P( -1.54 < z < 1.54) = normalcdf(-1.54, 1.54)= .8764