Question

Hello there! How to find the probability? See picture! Thank you and please show your work!

Answer 1

Answer:

  0.8914

Step-by-step explanation:

You want to find the z-values associated with the x-values:

 z = (x -μ)/σ

 z1 = (57 -90)/12 = -2.75

 z2 = (105 -90)/12 = 1.25

Look up these values in a probability table and find the difference of the table values.

 p(z < z1) ≈ 0.00298 . . . . from a table or calculator

 p(z < z2) ≈ 0.89435 . . . . from a table or calculator

p(57 < x < 105) ≈ 0.89435 -0.00298 = 0.89137 ≈ 0.8914