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:
x = 2
Step-by-step explanation:
These are known as alternate exterior angles. These types of angles are equal to each other.

Answer:
there is a greater chance that she selects a even number because there are 4 even numbers and 3 odd numbers
So the given angles are supplementary (add to 180). You take the two and add them. 21x+5+37x+1. This gets set to equal 180. 58x+6=180. Subtract 6 from both then divide by 58. You get x=3