Answer:
B
Explanation:
it means we assume that the progression between 2 interval points is linear (a straight line from the begin of the interval to the end of the interval).
so, a length of 9.5 in falls into the interval [9, 11].
in this interval we see that the change rate is (21 - 11)/(11 - 9) = 10/2 = 5/1
that means for every inch longer we expect 5 oz more.
the line equation there is
y = 5x + b
11 = 5×9 + b
11 = 45 + b
-34 = b
so, the line is
y = 5x - 34
for x = 9.5
y = 5×9.5 - 34 = 47.5 - 34 = 13.5 oz
B is with 13.4 the closest right answer.