The average electricity bill for Lynn’s home is $64.50 per month with a standard deviation of $8.20. In June she received a bill of only $30.00 because she was traveling for most of the month. How many standard deviations below the mean is the amount of Lynn’s electricity bill for June?
Accepted Solution
A:
This bill is about 4.21 standard deviations below the mean value.
To find this, first subtract the mean from the given amount.
30 - 64.5 = -34.5
Now, divide this by 8.2, which is the amount of 1 standard deviation.