Answer:175
Step-by-step explanation:
1. Turn 28% into a decima: 0.28
2. Multiply 1250 by 0.28 to get the amount of ninth grade students:350
3. Half the amount of ninth grade students:175
Since triangle DEF = triangle JKL, m<D = m<J, m<E = m<K, m<F = m<L.
m<F = m<L = 90 degrees
m<K = m<E = 5(m<D)
but m<E + m<D = 90 degrees [right angled triangle]
5(m<D) + m<D = 90 degrees
6(m<D) = 90 degrees
m<D = 90 / 6 = 15 degrees.
To check for continuity at the edges of each piece, you need to consider the limit as
approaches the edges. For example,

has two pieces,
and
, both of which are continuous by themselves on the provided intervals. In order for
to be continuous everywhere, we need to have

By definition of
, we have
, and the limits are


The limits match, so
is continuous.
For the others: Each of the individual pieces of
are continuous functions on their domains, so you just need to check the value of each piece at the edge of each subinterval.
0.4(420) = 4(420)/10
(0.4 is essentially 4/10)
1680/10 = 168
There are 168 sixth graders
If u add up 15,17, and 19 they add up to 51