Answer: Mean = 20 and standard deviation = 4
Step-by-step explanation:
Let x represents the success of getting the correct answer.
Here, the total number of trials(n) = 100
The probability of getting the correct answer, p = 1/5
Thus, the mean of the number of correct answer,



Now, the standard deviation, 



Thus, First option is correct.
The answer to this question is 22.83 but if you want it rounded its 22.84
Answer:
I’m pretty sure it’s B)- Z
Step-by-step explanation:
18. The correct table must display the following information.
38% prefer turkey with mayonnaise 20% prefer turkey with mustard 24% prefer ham with mayonnaise 18% prefer ham with mustard
In tables Z and W, each table totals 50 people.
To find the relative frequencies of the data in these tables, divide each number in the table by 50.
In tables X and Y, each table totals 100 people.
To find the relative frequencies of the data in these tables, divide each number in the table by 100.
The only table which is a possible representation of the data collected is table Z.
Likes Baseball
Does Not Like Baseball
Total
Likes Football Does Not Total Like Football
0.50 0.64 0.54
0.50 0.36 0.46 1.00 1.00 1.00
Mayonnaise Mustard
Total
Turkey
19 ÷ 50 = 0.38
10 ÷ 50 = 0.20
29 ÷ 50 = 0.58
Ham
12 ÷ 50 = 0.24
9 ÷ 50 = 0.18
21 ÷ 50 = 0.42
Total
31 ÷ 50 = 0.62
19 ÷ 50 = 0.38
50 ÷ 50 =1.00
Answer: 
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Work Shown:
Apply the following trig identity

Now let's rationalize the denominator

----------------------
As confirmation, you can use the idea that if x = y, then x-y = 0. We'll have x = tan(165) and y = -2+sqrt(3). When computing x-y, your calculator should get fairly close to 0, if not get 0 itself.
Or you can note how

which helps us see that they are the same thing.
Further confirmation comes from WolframAlpha (see attached image). They decided to write the answer as
but it's the same as above.