Okay, let me first explain what the equation<em> y = 8.77x + 686 </em>means
<em>y </em><em>is the hikers elevation </em>
Look at the graph and see what the y and x axis's are labeled as.
<em>x </em><em>is time. </em>
8.77 is just the slop of the trend line.
<em>686 </em><em>is just the elevation the hiker starts at</em>, or in technical terms, the y intercept. Y intercept is just where the lines touches the y axis.
The question asks what will be the <u>hiker's elevation at 145 minutes. </u>
To solve, just simply <u>plug in 145 as X </u>in the equation above. Remember x is time.
It will look like this :
y = 8.77 (145) + 686
Then solve.
y = 1271.65 + 686
y = 1957.65
Reminder: They want the nearest whole number!
Round 1957.65 feet to 1958 feet
Hope I helped! Message me if you have questions