Answer:
x = 11
Step-by-step explanation:
For part A add up all your students then add up all your students that like bike riding and skating (80+90) divide that by the total number of students who took the survey
For Part be put 20+40 over the toatl number of student then simplify

has critical points where the derivative is 0:

The second derivative is

and
, which indicates a local minimum at
with a value of
.
At the endpoints of [-2, 2], we have
and
, so that
has an absolute minimum of
and an absolute maximum of
on [-2, 2].
So we have



Radiation from the sun. That depends on the sun.