A recent study on the evolution of mankind shows that, with a few exceptions, world-record holders in the 100-meter dash have progressively gotten bigger over time (The Wall Street Journal, July 22,2009). The following table shows runners who have held the record, along with their recordholding times and heights:

Record Holder/Year Time

(in seconds)

Height

(in inches)

Eddie Tolan (1932) 10.30 67 Jesse Owens (1936) 10.20 70 Charles Greene (1968) 9.90 68 Eddie Hart (1972) 9.90 70 Carl Lewis (1991) 9.86 74 Asafa Powell (2007) 9.74 75 Usain Bolt (2008) 9.69 77 A portion of the Excel results from estimating Time = β 0 +

β 1 Height + ε are:

Coefficients Standard Error t Stat p-value Lower 95%

Upper 95%

Intercept 13.353 1.1714 11.3990 9.1E-05 10.34 16.36 Height − 0.0477 0.0163 0.0332 − 0.09 − 0.01

a. Formulate the estimated regression equation.

b. Specify the hypotheses to determine whether Height is linearly related to Time.

c. Calculate the value of the appropriate test statistic.

d. At the 5% significance level, is Height significant?

Explain.