Answer:
0.4460 = 44.60% probability that none of the 8 surnames of these authors were among the 10 most common
Step-by-step explanation:
For each surname, there are only two possible outcomes. Either they are among the 10 most common, or they are not. Each author is independent of each other. 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.
These names account for 9.6% of all U.S. residents.
This means that 
8 authors in total.
This means that 
What is the probability that none of the 8 surnames of these authors were among the 10 most common
This is
. So


0.4460 = 44.60% probability that none of the 8 surnames of these authors were among the 10 most common
The answer would be 5 if you draw it you would need to do a^2+b^2=c^2
You could do it as if they were fractions
.4 equals 4/10 which equals 2/5
.25 equals 25/100 which equals 1/4
2/5 times 1/4 equals 2/20
2/20 equals 1/10
1/10 equals .1
.1 is correct
You could also multiply decimals like this:
1.Multiply them together like full numbers
4 times 25 equals 100
2.Move the decimal in three times because the decimal .4 is moved in once and .25 is moved in twice so when you add them you get three
The answer would be .1 or .100 (it doesn't make a difference because you cross out any zeros at the end of a decimal Ex: .12300 equals .123 but .123001 stays .123001)
Answer:
Solve the resulting equation for x
The show the area of the school field to the power of ten, Mario simply
has to count the amount of zeros in 6,000. He will of course count 3
zeros, so the answer will be 6 x 10^(3).