Question

a) The weekly wages of employees of Volta gold are normally distributed about a mean of $1,250 with a standard deviation of $120. Find the probability of an employee having a weekly wage lying;

Answer 1

0.7102

0.8943

0.3696

Step - by - Step Explanation :

A.) Between $1320 and $970

P(Z < 1300) - P(Z < 970)

find the Zscore of each scores and their corresponding probability uinag the standard distribution table :

P(Z < (x - μ) /σ) - P(Z < (x - μ) / σ))

P(Z < (1320 - 1250) /120) - P(Z < (970 - 1250) / 120))

P(Z < 0.5833) - P(Z < - 2.333)

0.7200 - 0.0098 = 0.7102 (Standard

=0.7102

B.)Under 1400

x = 1400

P(Z < 400)

P(Z < (x - μ) /σ)

P(Z < (1400 - 1250) /120)

P(Z < 1.25) = 0.8943

C.) Over 1290

P(Z > 1290)

P(Z < (x - μ) /σ)

P(Z > (1290 - 1250) /120 = 0.3333

P(Z > z) = 1 - P(Z < 0.3333) = P(Z < 0.3333) = 0.6304

P(Z > 0.3333) = 1 - 0.6304 = 0.3696