The average speed of Joshua during that time is 2500 m/h.
Explanation:
It is given that Joshua started cycling at 5:15 pm. By 8:09 pm he has covered a distance of 7250 m.
The total time taken by Joshua from 5:15 pm to 8:09 pm is

Dividing we get,

Adding, we have,

Thus, the total time taken by Joshua is 
To determine the average speed we use the formula,

where
and 
Hence, substituting the values we have,

Dividing, we get,

Thus, the average speed of Joshua during that time is 2500 m/h.
The answer would be the median because you use the box plot to find the median. its the whole point of a box plot :)
4th quadrant is positive x (cos) and negative y (sin)
Use the Pythagorean Theorem to calculate the value of y (sin).
x² + y² = c²
5² + y² = 13²
25 + y² = 169
y² = 144
y = 12
Since the y-value is negative in the 4th quadrant, then y = -12

has gradient

which at the point (-1, 4, 3) has a value of

I'm not sure what the given direction vector is supposed to be, but my best guess is that it's intended to say
, in which case we have

Then the derivative of
at (-1, 4, 3) in the direction of
is

About 95% of scores fall in this range