Because triangle ABC is equilateral, FC is 9
Answer: A Yes, because the balls are randomly selected, the distances of the new ball can be compared to the distances of the original ball.
B Yes, because the original ball type is included in this experiment, the distances the different balls travel can be accurately compared.
Step-by-step explanation:
C No, because a placebo ball was not used, a comparison cannot be made to determine if the new ball travels significantly farther.
D No, because all of the new type of balls are not hit first, the distances they travel cannot be compared to the distances of the original ball.
The shortest distance they have to travel to return to their starting point is 9.4 miles.
Explanation
The joggers run 8 mile north and then runs 5 miles west. we have to calculate the shortest distance they have to travel to return to their starting point.
The distance traveled north and west respectively makes the height and base of a right angled triangle.
to find the shortest distance to the starting point, the hypotenuse has to be determined.
height h=8 miles
base b=5 miles
using pythagoras theorem

The shortest distance to the starting point is 9.4 miles