Answer:
The required confidence inteval = 94.9%.
Step-by-step explanation:
Confidence interval: Mean ± Margin of error
Given: A confidence interval for the true mean diameter of all oak trees in the neighbourhood is calculated to be (36.191, 42.969).
i.e. Mean + Margin of error = 42.969 (i)
Mean - Margin of error = 36.191 (ii)
Adding (i) and (ii), we get

Margin of error = 42.969-39.58 [from (i)]
= 3.389
Margin of error = 
here n= 25 
i.e.

Using excel function 1-TDIST.2T(2.054,24)
The required confidence inteval = 94.9%.
Answer:
The measure of angle C is 
Step-by-step explanation:
we know that
If AB || DC
then
-----> supplementary angles by consecutive interior angles
and remember that the sum of the interior angles in a trapezoid is equal to 360 degrees

step 1
Find the measure of angle D
substitute the measure of angle A
step 2
Find the measure of angle C

substitute the values


So what will it be a percentage of? it will be the percentage of the original recruits, of the original 150.
for this, we need to divide the number of recruits that left over all recruits, and multiply by 100%:

so the number of trainees decreased by 20 %