Answer:

Step-by-step explanation:
The logistic differential equation is as follows:

In this problem, we have that:
, which is the carring capacity of the population, that is, the maximum number of people allowed on the beach.
At 10 A.M., the number of people on the beach is 200 and is increasing at the rate of 400 per hour.
This means that
when
. With this, we can find r, that is, the growth rate,
So




So the differential equation is:


We determine line m as follows:
*First, by theorem we have the following:

Here m1 & m2 are the slopes of two perpendicular lines. For all lines that are perpendicular that is true, so we calculate the slope of line m using the slope of the function given [Which has a slope of 7/4]:

So, the slope of line m is -4/7. Now, using this slope and the point (-1, 4) we replace in the following expression:

Here x1, y1 & m1 are the x-component of the point, the y-component of the point, and the slope of the line respectively, so we replace and solve for y:


And that last function of y is the line m.
Jessica solved for the correct value of a, but Sally's review was incorrect.