Bridge tour. Refer to the eighth annual High Over China Bridge Tour for visiting several major suspensions and bridges under construction in China, discussed in Exercise 1.30. In addition, a record of the bridges’ height (in meters) and main span length (in meters) are saved in a file and the first five and last five observations are listed in the below table. Bridge Name Height (meters) Main Span Length (meters) Beipanjiang Bridge Duge 565 720 Siduhe Bridge 496 900 Puli Bridge 485 628 Jinshajiang Bridge Jin’an 461 1,386 Yachi Bridge 434 800 f f f Nujiang Railway Bridge Darui 212 490 Jinshajiang Bridge Hulukou 211 656 Xi'ninghe Bridge 210 470 Yelanghe Railway Bridge 210 370 Hezhang Bridge 210 180

a. Write the equation of a straight-line model relating the main span length (y) to the height (x) of the bridges.

b. The model, part

a, was fit to the data using software, as shown below. Find the least squares prediction equation on the printout.

c. List the assumptions required for the regression analysis.

d. Locate the estimated standard error of the regression model, s, on the printout.

e. Use the value of s to find a range where most (about 95%) of the errors of prediction will fall. SUMMARY OUTPUT Regression Statistics Multiple R 0.5948 R Square 0.3538 Adjusted R square 0.3482 Standard Error 233.3715 Observations 119 ANOVA df SS MS F Significance F Regression 1 3488260.5854 3488260.5854 64.0491 0.0000 Residual 117 6372083.3978 54462.2513 Total 118 9860343.9832 AGRI BRIDGE Coefficients Standard Error t-Stat P-value Lower 95% Upper 95% Lower 95.0% Upper 95.0% Intercept -272.6654 93.9387 -2.9026 0.0044 -458.7061 -86.6246 -458.7061 -86.6246 Height (meters) 2.6817 0.3351 8.0031 0.0000 2.0181 3.3453 2.0181 3.3453 Applying the Concepts—Intermediate