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anonymous
 one year ago
Suppose the number of students in a class for the Business Statistics program at a University has a mean of 23 with a standard deviation of 4.3. If 15 classes are selected randomly, find the probability that the mean number of students is between 20 and 30.
0.9699
0.9966
0.8412
0.6824
anonymous
 one year ago
Suppose the number of students in a class for the Business Statistics program at a University has a mean of 23 with a standard deviation of 4.3. If 15 classes are selected randomly, find the probability that the mean number of students is between 20 and 30. 0.9699 0.9966 0.8412 0.6824

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UsukiDoll
 one year ago
Best ResponseYou've already chosen the best response.0I haven't studied statistics. Sorry :/

phi
 one year ago
Best ResponseYou've already chosen the best response.2These are the population statistics: mean of 23 with a standard deviation of 4.3. \[ \mu = 23 ,\ \ \sigma= 4.3\] 15 classes are selected randomly represent a sample of size 15. The mean of this sample is also 23, but with a standard deviation \( \sigma_{sample}= \frac{1}{\sqrt{15}} \sigma\)

phi
 one year ago
Best ResponseYou've already chosen the best response.2the std dev of your sample means will be 4.3/sqrt(15) = 1.11 the limits 20 to 30 represent 3/1.11 to +7/1.11 or 2.7 to +6.3 std dev as the +6.3 above the mean is very far out in the tail, you can just find the area under the curve from 2.7 to infinity (or 1  area below 2.7)

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0@phi and how would you find the area under the curve ?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0so can i find it and tell you my answer to see if i get it right ?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0so i got C but i dont think that is correct

phi
 one year ago
Best ResponseYou've already chosen the best response.2you are looking for the area dw:1437654513070:dw

phi
 one year ago
Best ResponseYou've already chosen the best response.2can you post a copy of the table you are using ?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0i dont have one i just looked one up in google

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0i honestly just dont get this and i already went back to the lesson like 3 times to see if i could figure it out and i cant.

phi
 one year ago
Best ResponseYou've already chosen the best response.2what is the link to the table?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0wait would it be B ?

phi
 one year ago
Best ResponseYou've already chosen the best response.2the area you want for your problem starts at 2.7 and goes to the right your table shows the area starting on the left and going up to some std dev. this is opposite of your problem. BUT, because the curve is symmetric, you can use this table. find the value for z= 2.7

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0so where it say 2.7 i got there ?
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