Answer: 17.89
Step-by-step explanation:
In binomial distribution, the standard deviation is given by :-

As per given , we have
The number of vouchers in the sample with errors is denoted by x.
p= 0.20 , n = 2000
Then , 

Hence, the standard deviation of x is 17.89.
Answer:
A. 4x²+20x+25
Step-by-step explanation:
Because of PEMDAS, you calculate the value inside of the parenthesis first, so you expand [2x+1-(4x+6)]:
2x+1-4x-6 = -2x-5.
Then apply the exponent:
(-2x-5)² = (-2x-5)(-2x-5) = 4x²+10x+10x+25 = 4x²+20x+25
Answer:

Step-by-step explanation:
First we simplify:

Then we distribute:

Lastly, combine like terms:

Hope this helps!
Have a good evening! :)
Answer:
D
Step-by-step explanation: