Rahul performed an experiment using 16 windup rubber band single-propeller airplanes. He wound up the propeller a different number of times and recorded the amount of time (in seconds) that the airplane flew for each number of rotations that the propeller was wound. A regression analysis was performed and the partial computer output is given below. The regression equation is
Time = 0.924 + 0.0462 Rotations

Predictor Coef SE Coef T P
Constant 0.9241 0.6413 1.44 0.172
Rotation 0.04625 0.01565 2.96 0.010

S= 0.5426 ; R-Sq= 38.4% ; R -Sq(adj) =34.0%

Required:
What is a 95 percent confidence interval for the slope of the regression line that relates the number of rotations the rubber band is wound and the plane's flight time?

0.0462 ± 2.131(0.01565)

Step-by-step explanation:

The confidence interval for the slope, :

Slope Coefficient = 0.0462

Slope Coefficient ± Margin of error

Margin of Error = Tcritical * standard error

Standard Error (rotation) = 0.01565

We use T distribution, because sample size is small ; n = 16

Tcritical at 95% ; df = n - 1 = 16 - 1 = 15

Tcritical(0.05, 15) = 2.131

Hence,

Margin of Error = 2.131(0.01565)

Slope Coefficient for rotation = 0.0462

95% Confidence interval :

0.0462 ± 2.131(0.01565)

correct choice is b

step-by-step explanation:

when you calculate the average rate of change of a function, you are finding the slope of the secant line between the two points. for the function the average rate of change from point to point can be calculated as

to find the average rate of change from day 2 to day 10, note that at day 2, 8 houses were sold, so a(2,8) and at day 10, 2 houses were sold, so b(10,2). thus,