Let x be the age of a licensed driver in years. Let y be the percentage of all fatal accidents (for a given age) due to failure to yield the right of way. For example, the first data pair states that 5% of all fatal accidents of 37-year-olds are due to failure to yield the right of way.

x 37 47 57 67 77 87

y 5 8 10 18 28 43

Complete parts (a) through (e), given x = 372, y = 112, x2 = 24814, y2 = 3146, xy = 8234, and r 0.949

(b) Verify the given sums x, y, x2, y2, xy, and the value of the sample correlation coefficient r. (Round your value for r to three decimal places.)

x =

y =

x2 =

y2 =

xy =

r =

(c) Find x, and y. Then find the equation of the least-squares line y hat = a + bx. (Round your answers for x and y to two decimal places. Round your answers for a and b to three decimal places.)

x =

y =

y hat =

+

x

(d) Graph the least-squares line. Be sure to plot the point (x, y) as a point on the line.

(e) Find the value of the coefficient of determination r2. What percentage of the variation in y can be explained by the corresponding variation in x and the least-squares line? What percentage is unexplained? (Round your answer for r2 to three decimal places. Round your answers for the percentages to one decimal place.)

r2 =

explained

%

unexplained

%

(f) Predict the percentage of all fatal accidents due to failing to yield the right of way for 75-year-olds. (Round your answer to two decimal places.)

%