Anonymous
Anonymous asked in Science & MathematicsMathematics · 4 months ago

A normal population has a mean of 64 and a standard deviation of 13. You select a random sample of 9.?

Compute the probability that the sample mean is: (Round your z values to 2 decimal places and final answers to 4 decimal places):

(a) Greater than 66.

Probability:

(b) Less than 62.

Probability:

(c) Between 62 and 66.

Probability:

Update:

(I am able to find the z values, but I am getting lost when it comes to the rest of the calculations.)

2 Answers

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  • Mike G
    Lv 7
    4 months ago

    μ = 64 and σ = 13

    n = 9 so √n = 3

    x̅ = Sample mean

    a) z(x̅=66) = (66-64)/(13/3)

    = 0.4615

    From the z-tables

    P(z>0.4615) = 0.3228

    b) z(x̅=62) = (62-64)/(13/3) = -0.4615

    P(z<-0.4615) = 0.3228

    c) P(-0.4615<z<0.4615) = 0.3544

  • 4 months ago

    Do your own homework. If you don't understand it talk to your teacher. Me doing it for you won't teach you anything.

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