Question

For the linear model, y = -67.9x + 679 , the distance, in miles y, is a function of time, x, in hours. Use the model to calculate the total distance, in miles, at x = 5 hours.

1,018.5 miles
339.5 miles
9.9 miles
cannot be determined

Answer 1

To find the total distance \( y \) at \( x = 5 \) hours using the model \( y = -67.9x + 679 \), we can substitute \( x \) with 5:

\[
y = -67.9(5) + 679
\]

Calculating the first term:

\[
-67.9 \times 5 = -339.5
\]

Now substituting back into the equation:

\[
y = -339.5 + 679
\]

Calculating the total:

\[
y = 339.5
\]

Thus, the total distance at \( x = 5 \) hours is:

\[
\boxed{339.5 \text{ miles}}
\]