Question

Interpreting Solutions:

Answer 1

We have that
solution is
x <-10 or x>=25

for
x < -10
the solution is the interval (-∞, -10)

and 
for 
x>=25
the solution is the interval [25,∞)

therefore
the solution for
x <-10 or x>=25
is
(-∞, -10)  ∪ [25,∞)

the solution is any value of x less than -10 or greater than or equal to 25

Answer 2

The negative part of the solution set is ignored, because you cannot produce a negative number of phones.The company has at least an 80% success rate if the next 25 or more phones that are assembled work.Because the company has already made 10 phones and 7 are not working, if the next 25 phones work, the 35th phone puts the company at its goal of 80% or more.