5. The equation of the line of best fit of a scatter plot is f(x)=10.2217โˆ’0.0098x

, where ๐‘“ is the finishing time of the Olympic gold medalist in the menโ€™s 100 m dash, and ๐‘ฅ is the number of years since 1960.(1 point)
Part A: Interpret the ๐‘ฆ-intercept of the linear equation modeling the data.

The model suggests that the finishing time of the Olympic gold medalist in the menโ€™s 100 m dash in 1960 was
seconds

Part B: Interpret the slope of the linear equation that models the data.

The finishing time since 1960 has decreased each year by
seconds

Part C: The Summer Olympic Games, where the 100 m dash is run, occur every 4 years. By how many seconds does the model predict the first-place-finishing time will decrease every 4 years?

seconds.

1 answer

To analyze the linear equation \( f(x) = 10.2217 - 0.0098x \), where \( f(x) \) represents the finishing time of the Olympic gold medalist in the men's 100 m dash and \( x \) represents the number of years since 1960, letโ€™s address the parts one by one:

Part A: Interpret the \( y \)-intercept of the linear equation modeling the data.

The \( y \)-intercept occurs when \( x = 0 \). This corresponds to the year 1960 (since \( x \) is the number of years since 1960).

\[ f(0) = 10.2217 - 0.0098(0) = 10.2217 \]

Interpretation: The model suggests that the finishing time of the Olympic gold medalist in the men's 100 m dash in 1960 was 10.2217 seconds.


Part B: Interpret the slope of the linear equation that models the data.

The slope of the line is \(-0.0098\). This value represents the rate of change of the finishing time concerning the years since 1960.

Interpretation: The finishing time since 1960 has decreased each year by 0.0098 seconds.


Part C: The Summer Olympic Games, where the 100 m dash is run, occur every 4 years. By how many seconds does the model predict the first-place finishing time will decrease every 4 years?

To find the total decrease over 4 years, we can multiply the slope by 4:

\[ \text{Decrease over 4 years} = -0.0098 \times 4 = -0.0392 \]

Answer: The model predicts the first-place finishing time will decrease by 0.0392 seconds every 4 years.