Letxbe the age in years of a licensed automobile driver. Letybe the percentage of all fatal accidents (for a given age) due to speeding. For example, the first data pair indicates that35%of all fatal accidents of 17-year-olds are due to speeding.

x: 17 27 37 47 57 67 77

y: 35 23 21 12 10 7 5

Complete parts (a) through (e), givenx=329,y=113,x²=18,263,y²=2513,xy=3981, andr0.958.

(a) Draw a scatter diagram displaying the data.

(b) Verify the given sumsx,y,x²,y²,xyand the value of the sample correlation coefficientr. (Round your value forrto three decimal places.)

x=

y=

x²=

y²=

xy=

r=

(c) Findx, andy. Then find the equation of the least-squares line=a+bx. (Round your answers forxandyto two decimal places. Round your answers foraandbto three decimal places.)x=y==+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 determinationr².

What percentage of the variation inycan beexplainedby the corresponding variation inxand the least-squares line? What percentage isunexplained? (Round your answer forr²to 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 speeding for45-year-olds. (Round your answer to two decimal places.)

%