8/11 cant be an improper fraction because the numerator is smaller than the denominator
Answer:
(47.3, 54.1)
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of
.
That is z with a pvalue of
, so Z = 1.96.
Now, find the margin of error M as such

In which
is the standard deviation of the population and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 50.7 - 3.4 = 47.3
The upper end of the interval is the sample mean added to M. So it is 50.7 + 3.4 = 54.1
The answer is (47.3, 54.1).
6x + 4x+6 + 8x+3 = 63
6x+4x+8x = 63 - 3 - 6
18x = 54
x = 54/18
x = 3
Side AB = 6(3) = 18
Side AC = 4(3)+6 = 18
Side BC = 8(3)+3 = 27