SOLUTION: If the mean income of plumbers is $3000 a month and the standard deviation is $300, what per cent of plumbers make between $3000 and $3300?

Algebra ->  Customizable Word Problem Solvers  -> Finance -> SOLUTION: If the mean income of plumbers is $3000 a month and the standard deviation is $300, what per cent of plumbers make between $3000 and $3300?      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 253080: If the mean income of plumbers is $3000 a month and the standard deviation is $300, what per cent of plumbers make between $3000 and $3300?
Answer by hokies(65) About Me  (Show Source):
You can put this solution on YOUR website!
Use a z-table. One is located at: http://www.easyhomeworkhelp.com/statistics/ztable.jpg
+1 standard deviation is the same as a z-score of 1.0. From the table, it has a z-score = .8413. Therefore, 84.13% of plumbers make less than $3300, and 1-.8413=.1587, or 15.87% of plumbers make more than $3300.
Hope this helps! :-)