Answer :
On a test that has a normal distribution, a score of 41 falls three standard deviation below the mean, and a score of 73
folle one standard deviation above the moon. Determine the mean of the test.
we know that
3=(mean-41)standard deviation -------> first equation
1=(73-mean)/standard deviation ------> second equation
solve the system of equations
Isolate deviation standard
sd=(mean-41)/3
sd=73-mean
73-mean=(mean-41)/3
219-3mean=mean-41
3mean+mean=219+41
4 mean=178