Question

6

From 1988 to 2008, the number B of federally insured banks could be approximated by B(t)=−324t+13741 where t is the year and t=0 corresponds to 1988.



Find the slope of the graph of B.

Interpret this slope as a rate of change. Choose the correct answer below.

• The number of banks decreased by 324 banks per year
• The number of banks increased by 324 banks per year
• The number of banks increased by 13741 banks per year
• The number of banks increased by -324 banks per year
• The number of banks decreased by -324 banks per year
• The number of banks decreased by 13741 banks per year

Find the y-intercept of the graph of B.
The y-intercept is

Interpret the y-intercept. Choose the correct answer below.

• The y-intercept is the minimum number of banks allowed in the country
• The y-intercept is the maximum number of banks allowed in the country
• The y-intercept is the number of banks in 1993
• The y-intercept is the number of banks in 1988
• The y-intercept is the number of banks in 2008

11

A regression was run to determine if there is a relationship between hours of TV watched per day (x) and number of situps a person can do (y).

The results of the regression were:

     y=ax+b
     a=-0.806
     b=22.347

Use this to predict the number of situps a person who watches 12.5 hours of TV can do (round to one decimal place)