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wiley plus.com/edugen/student/mainfrunl ORION Assignment ignment BACK PRINTER VE

ID: 3149978 • Letter: W

Question

wiley plus.com/edugen/student/mainfrunl ORION Assignment ignment BACK PRINTER VERSION Question 29 A bank officer wants to determine the amount of the average total monthly deposits per austomer at the bank. He believes an estimate of this average amount using a confidence interval is sufficient, How large a sample should he take to be within $200 of the actual average with 99% confidence? He assumes the standard deviation of total monthly deposits for all customers is about $1.000. (Round your answer up to the nearest integer) Question Attempts: 0 of 2 used SAVE FOR LATER DUOMITANSwER Copyright 2000-2016 by John Wiley & Sons, Inc. or related companies. Ai rights reserved. Polka I 2000-2016 sans uns. Aa Rights Reserved. A Division of lohn wley.A sons Inc. Version 4.17.3 MacBook Air

Explanation / Answer

This is the exact answer USING TECHNOLOGY:

Note that      
      
n = z(alpha/2)^2 s^2 / E^2      
      
where      
      
alpha/2 = (1 - confidence level)/2 =    0.005  
      
Using a table/technology,      
      
z(alpha/2) =    2.575829304  
      
Also,      
      
s = sample standard deviation =    1000  
E = margin of error =    200  
      
Thus,      
      
n =    165.872415  
      
Rounding up,      
      
n =    166   [ANSWER]

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If you use tables, we round z to 2.58.

Note that      
      
n = z(alpha/2)^2 s^2 / E^2      
      
where      
      
alpha/2 = (1 - confidence level)/2 =    0.005  
      
Using a table/technology,      
      
z(alpha/2) =    2.58  
      
Also,      
      
s = sample standard deviation =    1000  
E = margin of error =    200  
      
Thus,      
      
n =    166.41  
      
Rounding up,      
      
n =    167   [ALTERNATIVE ANSWER, USING TABLES]