Directions: Read carefully. These questions pertain to linear, and other, regressions.

1.  The relationship between the number of widgets in a package and the length of the package, in inches, is given in the table at the right. What is the slope of the least squares regression line (the line of best fit)? (Widgets on x-axis, Length on y-axis)
Choose:
 0.25 0.5 0.75 1
 Number of Widgets Length of Package (in.) 3 9.00 4 9.25 5 9.50 6 9.75

What is the value of the y-intercept of the least squares line?
Choose:
 9 8.75 8.5 8.25

2.  The table below shows the relationship between total fat grams and the total calories in a selection of fast food sandwiches. Find the linear regression equation that models this data. (Round to nearest integer with Fat on x-axis and Calories on y-axis.)
Choose:
 y = 14x + 99 y = 14x + 98 y = 13x + 143 y = 13x + 142
 Total Fat (g) 9 13 21 30 31 32 34 Total Calories 260 320 420 530 560 580 590

3.  A cup of hot coffee is poured into a travel mug. The mug is taken out into the wintery weather and begins to cool down over 5 minutes. Using an exponential regression equation to model the drop in temperature, predict the temperature of the coffee after 6 minutes, to nearest degree.
(Time on x-axis and Temp. on y-axis)
Choose:
 76º 80º 85º 87º
 Time (minutes) Temp. º F. 0 180 1 160 2 138 3 125 4 110 5 95

4.  A morning radio talk show is running a "Winter Coat Campaign" to collect and deliver coats to local shelters. They are storing the coats until they reach their goal of 2100 coats. The table at the right shows the number of coats in storage at the end of each day of the campaign.
a) Which equation is the linear regression equation for this data
(rounded to nearest hundredths with Days on x-axis and Coats on y-axis)?
 Day of Campaign Number of Coats Stored 1 860 2 930 3 1000 4 1150 5 1200 6 1360
Choose:
 y = 98.86 + 737.33x y = 98.86x + 737.33 y = 97.76 + 737.33x y = 97.76x + 737.33
b) Using the equation from part a, predict the day the campaign will meet its goal and the coats will be delivered to the shelters.
Choose:

 Day 10 Day 12 Day 14 Day 16

5.  A research study finds that fat calories in hamburger have a positive linear association with the amount of sodium found in the hamburger. This finding indicates that:
 Choose: low amounts of sodium in hamburgers indicates a high number of fat calories in hamburger. high amounts of sodium in hamburgers cause high amounts of fat calories in hamburger. hamburgers with low amounts of fat calories tend to have low amounts of sodium. hamburgers with low amounts of fat calories have high amounts of sodium.