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2 years ago

1. The sum of two numbers is 81. The difference is 13. Find the two numbers.

Mathematics

2 answers:

bezimeni [28]2 years ago

7 0

Answer:

47 and 34

Step-by-step explanation:

x+x-13=81

2x-13=81

2x=94

x=47

y=34

34+47=81

Zepler [3.9K]2 years ago

3 0

47 and 34 are the answers thank you

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

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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

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

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

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

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

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

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

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

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

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

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.

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2 years ago

A total of 31,000 is to be invested, some in bonds and some in certificates of deposit (CDs). If the amount invested in bonds is

kupik [55]

Answer:

Bonds: $42,000

Certificates of deposit: $41,000

Step-by-step explanation:

Total invested = Amount in bonds + Amount in CDs

Amount in bonds = Amount in CDs + 1000

Let the amount in bonds = B and the amount in CDs = C

1. 83,000 = B + C

2. B = C+1000

Since the above expression (#2) defines B, you can substitute it for the B in the first equation (#1).

83,000 = C + 1000 + C

Now, you can solve for C.

83,000 = 2C + 1000

82,000 = 2C

41,000 = C

You know that the amount invested in bonds is $1000 greater than the amount invested in CDs, so add $1000 to C and you find B, $42,000.

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For each right triangle below, find the missing side (Pythagorean’s Theorem) and the missing angle (Angle Sum theorem.)

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Answer: 180

i thank hopeful \

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2 years ago

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