For a study conducted by the research department of a pharmaceutical company,280

randomly selected individuals were asked to report the amount of money they spend annually on prescription allergy relief medication. The sample mean was found to be$

17.70

with a standard deviation of$

5.40

. A random sample of200

individuals was selected independently of the first sample. These individuals reported their annual spending on non-prescription allergy relief medication. The mean of the second sample was found to be$

18.30

with a standard deviation of$

4.40

. As the sample sizes were quite large, it was assumed that the respective population standard deviations of the spending for prescription and non-prescription allergy relief medication could be estimated as the respective sample standard deviation values given above. Construct a90

%

confidence interval for the difference

1

2

between the mean spending on prescription allergy relief medication (

1

) and the mean spending on non-prescription allergy relief medication (

2

). Then complete the table below.

What is the lower limit of the 90% confidence interval

What is the upper limit of the 90% confidence interval