Question

Brianna went hiking.
Brianna's altitude (in meters above sea level) as a function of time (in hours) is graphed.
What is the approximate average rate at which Brianna's altitude increases, between the
\[7^\text{th}\] and the
\[11^\text{th}\] hour marks?
The first quadrant of a coordinate plane. The x-axis scales by one and is labeled time in hours. The y-axis scales by ten and is labeled altitude in meters. The graph is a continuous curve. It starts at the y-intercept zero, forty and increases at a non linear rate through the point two, sixty, the point four, sixty-six, the point seven, sixty-five, the point eleven, one hundred five. Then it decreases to fourteen, one hundred. All values are estimates.
\[\small{2}\]
\[\small{4}\]
\[\small{6}\]
\[\small{8}\]
\[\small{10}\]
\[\small{12}\]
\[\small{20}\]
\[\small{40}\]
\[\small{60}\]
\[\small{80}\]
\[\small{100}\]
\[\small{120}\]
Choose 1 answer:
A
\[9.7\] meters per hour
B
\[10\] meters per hour
C
\[10.3\] meters per hour
D
\[10.6\] meters per hour

Answer 1

Average rate = (altitude at 11 h − altitude at 7 h) / (11 − 7) = (105 − 65) / 4 = 40 / 4 = 10 meters/hour.

Answer: B