n a study of exhaust emissions from school buses, the pollution intake by passengers was determined for a sample of nine school buses used in the a school district. The pollution intake is the amount...

n a study of exhaust emissions from school buses, the pollution intake by passengers was determined for a sample of nine school buses used in the a school district. The pollution intake is the amount of exhaust emissions, in grams per person, that would be breathed in while travelling on the bus during its usual 10-mile trip on congested highways. Here are the amounts for the nine buses when driven with the windows open:

The data can be accessedHERE.
Find a 90% confidence interval to estimate the population mean pollution intake μμ by completing the following.

1. The sample mean x¯=x¯=
   
   
   
   


2. The standard error SE=SE=
   
   
   
   


3. The tt-critical value t∗=t∗=
   
   
   
   


4. Lower end of the confidence interval L=L=
   
   
   
   


5. Upper end of the confidence interval U=U=
   
   
   
   


6. What is the margin of error?  ME=ME=