Linear Regression

The ages (in years) and the number of hours of sleep in one night for 7 adults is shown. Given

y = -0.09x + 10.45, predict the hours of sleep for someone that is 68 years old.

• 16.57 hours

• -4.33 hours

• -16.57 hours

• 4.33 hours

The linear regression equation is y = 61.93x - 1.79.  Use the equation to predict how far this person will travel after 10 hours of driving.

• 10 miles
• 617.5 miles
• 0.19 miles
• 500 miles

The linear regression equation is y = 61.93x - 1.79.  According to the model, the slope can be interpreted as:

• After 0 hours of driving, they went 61.93 miles.
• They drove at a speed of 61.93 miles per hour.
• They drove 61.93 miles total.
• They drove 61.93 hours total.

Using your linear regression, what is y when x is 30?

• 61.59
• 52.46
• 57.94
• 59.76

The equation y = -2x + 7 models the amount of gas remaining in a lawnmower after x hours of use since it was filled. What is the meaning of the slope?

• For each hour of mowing, the mower is predicted to use 2 gallons.

• the predicted amount of gas the lawnmower can hold is 2 gallons

• For every two hours of mowing, the mower is predicted to use 7 gallons.

• The predicted amount of gas remaining after 1 hour is 2 gallons.

Rich is a member of a gym. He pays a monthly fee plus a per-visit fee. The equation below represents the monthly amount Rich pays for his membership to the gym per month for x visits.

y= 10 + 3x

What does the y-intercept of the graph of this equation represent?

• The monthly fee

• How much Rich pays per visit

• The number of times Rich goes to the gym

• The total cost at the end of the month

Which graph represents data that has a correlation coefficient close to -1?

• 
• 
• 
• 

Coefficient of correlation lies between

• 0 and +1

• 0 and -1

• -1 and +1

• -5 and +5

Answer explanation

The value of r must be between -1 and +1