SOLUTION: Let X be normally distributed with mean μ = 142 and standard deviation σ = 28. [You may find it useful to reference the z table.] a. Find P(X ≤ 100). (Round "z" value to 2

Algebra ->  Probability-and-statistics -> SOLUTION: Let X be normally distributed with mean μ = 142 and standard deviation σ = 28. [You may find it useful to reference the z table.] a. Find P(X ≤ 100). (Round "z" value to 2      Log On


   

Question 1162929: Let X be normally distributed with mean μ = 142 and standard deviation σ = 28. [You may find it useful to reference the z table.]

a. Find P(X ≤ 100). (Round "z" value to 2 decimal places and final answer to 4 decimal places.)


b. Find P(95 ≤ X ≤ 110). (Round "z" value to 2 decimal places and final answer to 4 decimal places.)


c. Find x such that P(X ≤ x) = 0.400. (Round "z" value and final answer to 3 decimal places.)


d. Find x such that P(X > x) = 0.800. (Round "z" value and final answer to 3 decimal places.)



Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
z < (100-142)/28 which is -1.50
probability 0.0668
z is between -47/28=-1.68 and -32/28=-1.14
probability is 0.0807
z=-0.2533, and x is -0.2533=(x-mean)/sd
or -7.094=x-mean
pr x=134.906
z=0.842
do same way
23.576=x-mean
x=165.576