Answer: The z-scores for Stephan's IL and FL electric bills. are -0.625 and 0.75 respectively.
Step-by-step explanation:
Given: Average monthly electric bill in Illinois = $83
Average monthly electric bill in Florida = $102
Formula of z :
In Illinois, the mean monthly electric bill is $85, with a standard deviation of $3.20.
In Florida, the mean monthly electric bill is $105, with a standard deviation of $4.00.
Hence, the z-scores for Stephan's IL and FL electric bills. are -0.625 and 0.75 respectively.