Answer:
First Question 
 lower limit of 9 mph 

 upper limit of 9 mph 
 
Second Question
lower limit of 120 pounds is 

 upper limit of 120 pounds is 
 
Third Question
lower limit of 187 pounds is 

 upper limit of 187 pounds is 
 
Explanation:
From the question we are told that 
 The amount of beer administered is three 12-ounce beers
 The amount of coffee administered is two cups of coffee
 The speed limit is 60-mph
 The smallest unit of scale is 1 mph
 The first subject scores 9 mph
Generally given that the smallest unit of scale is 1 mph then the deviation of 9 mph will be by 

Hence the lower limit of 9 mph is 
 

 

And the upper limit of 9 mph is
 

 
 
Generally given that the measuring weight on a scale that is accurate to the nearest 0.2 pound then 120 pounds will deviate by 

Hence the lower limit of 120 pounds is 
 

 

And the upper limit of 120 pounds is
 

 
 
Generally given that the measuring weight on a scale that is accurate to the nearest 0.5 pound then 187 pounds will deviate by 

Hence the lower limit of 120 pounds is 
 

 

And the upper limit of 120 pounds is
 
