Answer
The rate of change in altitude between points B and C is $\dfrac{7}{-4}$ yards per second.
Work Step by Step
The rate of change of altitude between points B(6, 20) and C(10, 13) is actually the slope of the line connecting the two points.B and C to have:
$\\\\\text{rate of change in altitude}
\\\\=\dfrac{20-13}{6-10}
\\\\=\dfrac{7}{-4}$
