STATE: Does the physiology of women make them better suited than men to longdistance running? Will women eventually outperform men in longdistance races? Researchers examined data on world record times (in seconds) for men and women in the marathon. Based on these data, researchers (in 1992) attempted to predict when women would outrun men in the marathon. The tables contain the data for women and for men.

Year	1926	1964	1967	1970	1971	1974	1975
Time	13222.0	11973.0	11246.0	10973.0	9990.0	9834.5	9499.0
Year	1977	1980	1981	1982	1983	1985
Time	9287.5	9027.0	8806.0	8771.0	8563.0	8466.0

Year	1908	1909	1913	1920	1925	1935	1947
Time	10518.4	9751.0	9366.6	9155.8	8941.8	8802.0	8739.0
Year	1952	1953	1954	1958	1960	1963	1964
Time	8442.2	8314.8	8259.4	8117.0	8116.2	8068.0	7931.2
Year	1965	1967	1969	1981	1984	1985	1988
Time	7920.0	7776.4	7713.6	7698.0	7685.0	7632.0	7610.

PLAN: Analyze these data using leastsquares regression to estimate when men and women's record times will be equal. How reliable is your estimate? (You may wish to look online to find the current men's and women's record times.)

SOLVE: Find the leastsquares regression line for predicting record time from year for women.

A. =182976.1587.73

B. =87.73182976.15

C. =182976.15+87.73

D. =2066+0.009445

E. =182976.1587.73

F. =0.0094452066

G. =182976.15+87.73

H. =20660.009445

Find the leastsquares regression line for predicting record time from year for men.

A. =0.030642210

B. =29.535-66,072

C. =66072+29.535

D. =29.535+66,072

E. =66072-29.535

F. =22100.03064

G. =2210+0.03064

H. =66072-29.535

CONCLUDE: Use leastsquares regression to estimate when men and women's record times will be equal. Choose the correct statement.

A. Using the regression lines plotted, we might expect women to outrun men by the year 2009.

B. Using the regression lines plotted, we might expect women to outrun men by the year 2029.

C. Using the regression lines plotted, we might expect women to outrun men by the year 1980.

D. Using the regression lines plotted, we might expect women to outrun men by the year 1998.