Answer:
99% Confidence interval:  (2.9,6.7)    
Step-by-step explanation:
We are given the following data set:
1.8, 4.7, 4.1, 5.2, 7.6, 7.3, 5.7, 3.2, 5.4, 1.9, 2.7, 8.1
Formula:
 
  
where  are data points,
 are data points,  is the mean and n is the number of observations.
 is the mean and n is the number of observations.  


Sum of squares of differences = 51.18

99% Confidence interval:  
 
  
Putting the values, we get,  
 
  
 
  
(2.9,6.7) is the required 99% confidence interval for average number of hours per day adults spend in front of screens watching television-related content.