Answer
$4\leq x<10$
Work Step by Step
This is a half-open interval
(one endpoint included, the other excluded).
The left endpoint, 4 is included in the interval,
while the right endpoint, 10, is not..
$($9.99, 9.9999, 9.9999999 etc. are in the interval,
but 10 itself is not)
So if x is a number in this interval, it will be
between 4 and 10 , with the possibility of being
4 or greater and less than ten (but not equal to ten). .
We can write this as
$4\leq x<10$
