Answer:
55.2% probability that the customer is charged incorrectly on at least 3 items.
Step-by-step explanation:
For each item, there are only two possible outcomes. Either it is charged incorrectly, or it is not. The probability of an item being charged incorrectly is independent from other items. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
A survey finds customers are charged incorrectly for an item 20% of the time.
This means that 
Find the probability that the customer is charged incorrectly on at least 3 items.
Either the customer is charged incorrectly on 2 or less items, or he is charged on at least 3. The sum of the probabilities of these events is 1.
So

We want 
So

In which







55.2% probability that the customer is charged incorrectly on at least 3 items.
Answer:
x = 60°
Step-by-step explanation:
Use special triangles.
Starting with an equilateral triangle (all angles at 60°) with the side length of 2. Drop an altitude from one of the vertices to cut in half and make a right - triangle.
The hypotenuse length is 2. The base length, because it was cut in half, is 1. The height can be found with the Pythagorean theorem, which is √3.
The ratio for tangent is opposite over adjacent.
Since √3 = √3 / 1, the angle must be the one as marked in the picture.
Remember this triangle came from an equilateral triangle, so that angle is 60°. It was not cut in half, unlike the top angle which is 30°.
you have to find how many feet r in a mile then divid that by 60 sec.
Answer:
It is always important to go through the given problem first to get a concept of the requiremement. Then all the information's available from the question has to be noted down in such a manner that there would be no need to look at the question while solving.
Total number of students wearing jeans = 10
Total number of students wearing shorts = 9
Total number of students wearing capris = 2
Then the total number of students surveyed by Mrs Lane = (10 + 9 + 2)
= 21
Now percentage of students wearing shorts = (9/21) * 100
= (3/7) * 100
= 300/7
= 42.85 percent
So a total percentage of 42.85% of the students were wearing shorts.
Step-by-step explanation: