Which step would not be a possible first step for solving the following equation algebraically?

In the United States, voters who are neither Democrat nor Republican are called Independent. It is believed that 11% of voters a

Radda [10]

Answer:

a) 0.0214 = 2.14% probability that none of the people are Independent.

b) 0.8516 = 85.16% probability that fewer than 6 are Independent.

c) 0.8914 = 89.14% probability that more than 2 people are Independent.

Step-by-step explanation:

For each people, there are only two possible outcomes. Either they are independent, or they are not. For each person asked, the probability of them being Independent voters is the same. This means that 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.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

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

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

It is believed that 11% of voters are Independent.

This means that $p = 0.11$

A survey asked 33 people to identify themselves as Democrat, Republican, or Independent.

This means that $n = 33$

A. What is the probability that none of the people are Independent?

This is P(X = 0). So

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 0) = C_{33,0}.(0.11)^{0}.(0.89)^{33} = 0.0214$

0.0214 = 2.14% probability that none of the people are Independent.

B. What is the probability that fewer than 6 are Independent?

This is

$P(X < 6) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) + P(X = 5)$

So

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 0) = C_{33,0}.(0.11)^{0}.(0.89)^{33} = 0.0214$

$P(X = 1) = C_{33,1}.(0.11)^{1}.(0.89)^{32} = 0.0872$

$P(X = 2) = C_{33,2}.(0.11)^{2}.(0.89)^{31} = 0.1724$

$P(X = 3) = C_{33,3}.(0.11)^{3}.(0.89)^{30} = 0.2202$

$P(X = 4) = C_{33,4}.(0.11)^{4}.(0.89)^{29} = 0.2041$

$P(X = 5) = C_{33,5}.(0.11)^{5}.(0.89)^{28} = 0.1463$

$P(X < 6) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) + P(X = 5) = 0.0214 + 0.0872 + 0.1724 + 0.2202 + 0.2041 + 0.1463 = 0.8516$

0.8516 = 85.16% probability that fewer than 6 are Independent.

C. What is the probability that more than 2 people are Independent?

This is:

$P(X \geq 2) = 1 - P(X < 2)$

In which

$P(X < 2) = P(X = 0) + P(X = 1)$

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 0) = C_{33,0}.(0.11)^{0}.(0.89)^{33} = 0.0214$

$P(X = 1) = C_{33,1}.(0.11)^{1}.(0.89)^{32} = 0.0872$

$P(X < 2) = 0.0214 + 0.0872 = 0.1086$

$P(X \geq 2) = 1 - P(X < 2) = 1 - 0.1086 = 0.8914$

0.8914 = 89.14% probability that more than 2 people are Independent.

8 0

2 years ago

If a =3 and b= -1, what is the value of ab-b to the second power?

Scilla [17]

Answer: -16

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5 0

3 years ago

Sam has 13 1/2 yards of ribbon. He cuts them 3/4 yards . What is the maximum numbers of pieces of ribbon

german

Answer:

18

Step-by-step explanation:

You basically have to do 13.5 divided by 0.75 (3/4) which equals 18

4 0

3 years ago

125 thousandths = 1 tenth and ______ thousandths..... HELP

Evgen [1.6K]

125 thousandths is the same as .125
Since decimals go tenths, hundredths, thousandths......
you would just say how many this decimal has, so it has 1tenth and 25 thousandths.

3 0

3 years ago

If you add 12 to my number and then multiply the result by 3, you will get 64 more than two-thirds of my number. Find my number.

anastassius [24]

Answer:

The number is 12

Step-by-step explanation:

[] First, let's turn all these words into something mathematical. N will equal "my number"

-> If you add 12 to my number and then multiply the result by 3, you will get 64 more than two-thirds of my number.

-> n + 12 and then multiply the result by 3, you will get 64 more than two-thirds of my number.

-> 3(n + 12), you will get 64 more than two-thirds of my number.

-> 3(n + 12) = 64 more than $\frac{2n}{3}$

-> 3(n + 12) = 64 + $\frac{2n}{3}$

[] Phew, okay. Now it is something we can solve and less scary;

[Given]

3(n + 12) = 64 + $\frac{2n}{3}$

[Distribute]

3n + 36 = 64 + $\frac{2n}{3}$

[Multiply both sides by 3]

9n + 108 = 192 + 2n

[Subtract 108 and 2n from both sides]

7n = 84

[Divide both sides by 4]

n = 12

Have a nice day!

I hope this is what you are looking for, but if not - comment! I will edit and update my answer accordingly. (ノ^∇^)

- Heather

8 0

3 years ago