Problem 6-21 (Algorithmic)

The Centers for Disease Control and Prevention Office on Smokingand Health (OSH) is the lead federal agency responsible forcomprehensive tobacco prevention and control. OSH was establishedin 1965 to reduce the death and disease caused by tobacco use andexposure to secondhand smoke. One of the many responsibilities ofthe OSH is to collect data on tobacco use. The following data showthe percentage of U.S. adults who were users of tobacco for arecent 11-year period.

Year	Percentage of Adults Who Smoke
1	22.8
2	21
3	20.5
4	20.5
5	20.5
6	19
7	19.4
8	20.2
9	20.2
10	19.3
11	18.9

1. Choose the correct time series plot.
   

   (i)		(ii)
   (iii)		(iv)

   
   
   
   What type of pattern exists in the data?
   
   
   
2. Use simple linear regression analysis to find the parametersfor the line that minimizes MSE for this time series. Do not roundyour interim computations and round your final answers to threedecimal places. For subtractive or negative numbers use a minussign. (Example: -300)
   
   y-intercept, b₀ =
   
   Slope, b₁ =
   
   MSE =
   
3. One of OSH’s goals is to cut the percentage of U.S. adults whowere users of tobacco to 12% or less within nine years of the lastyear of these data. Does your regression model from part (b)suggest that OSH is on target to meet this goal?
   
   
   
   Use your model from part (b) to estimate the number of years thatmust pass after these data have been collected before OSH willachieve this goal. Round your answer to the nearest wholenumber.
   
   years