SOLUTION: A shoe manufacturer collected data regarding men's shoe sizes and found that the distribution of sizes exactly fits the normal curve. If the mean shoe size is 11 and standard devia

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Question 1204371: A shoe manufacturer collected data regarding men's shoe sizes and found that the distribution of sizes exactly fits the normal curve. If the mean shoe size is 11 and standard deviation is 1.5, find (A) the probability that a man's shoe size is greater than or equal to 11. (B) the probability that a man's shoe size is greater than or equal to 12.5
I know that I have to standardize by using the Z-score formula, I can't figure out the X value in formulas

Answer by ikleyn(52834) About Me  (Show Source):
You can put this solution on YOUR website!
.
A shoe manufacturer collected data regarding men's shoe sizes and found that the distribution
of sizes exactly fits the normal curve. If the mean shoe size is 11 and standard deviation is 1.5, find
(A) the probability that a man's shoe size is greater than or equal to 11.
(B) the probability that a man's shoe size is greater than or equal to 12.5
I know that I have to standardize by using the Z-score formula, I can't figure out the X value in formulas
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X-value in formulas is the mean value.


Z-values in formulas are the raw sizes.


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Comment from student : Thank you for your response but could please show me how to set up the z-score for part A
because I am still not understanding. I figured out part B.


My response :
    You calculate the standardized z-score  Z = %28z-x%29%2Fs = %2811-11%29%2F1.5 = 0  and then from the standard 
    table find the probability  P(Z >= 0) = 0.5.   It is your ANSWER for part (A).