Answer: OPTION A.
Step-by-step explanation:
First you must calculate the lenght of the side DF by applying the Pythagorean theorem, as following:

Now you can find sin(E) as you can see below:

Where:

Then:


Answer:
D 1/4
Step-by-step explanation:
Well brake 7 into 5 and 2 and then just multiply it by 3 so it would be 5 x3=15 and 2x3=6 then u add 15+6 it would be the sum, of 21 so 3x7=21
Answer:
19 beers must be sampled.
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 Z-table as such z has a p-value of
.
That is z with a pvalue of
, so Z = 1.645.
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 population standard deviation for the temperature of beers found in Scooter's Tavern is 0.26 degrees.
This means that 
If we want to be 90% confident that the sample mean beer temperature is within 0.1 degrees of the true mean temperature, how many beers must we sample?
This is n for which M = 0.1. So






Rounding up:
19 beers must be sampled.