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2 years ago

Prove that x is a subset of y then x union z is a subset of y union z for all sets x y and z

Mathematics

1 answer:

Ganezh [65]2 years ago

4 0

We are to show that if X ⊆ Y then (X ∪ Z) ⊆ (Y ∪ Z) for sets X, Y, Z.

Assume that a is a representative element of X, that is, a ∈ X. By the definition of union, a ∈ X ∪ Z. Now because X ⊆ Y and we assumed a ∈ X, then a ∈ Y by the definition of subset. And because a ∈ Y, then a ∈ Y ∪ Z by definition of union.

We chose our representative element, a, and showed that a ∈ X ∪ Y implies that a ∈ Y ∪ Z and this completes the proof.

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$53,000 is placed in an investment account that grows at a fixed rate of 2% (compound growth) per year. how much is in the accou

ella [17]

Answer:

$57,369

Step-by-step explanation:

We have been given that an amount of $53,000 is placed in an investment account that grows at a fixed rate of 2% (compound growth) per year. We are asked to find the amount in the account after 4 years.

To solve our given problem we will use compound interest formula.\

$A=P(1+\frac{r}{n})^{nt}$ , where,

A = Final amount after t years,

P = Principal amount,

r = Annual interest rate in decimal form,

n = Number of times interest is compounded per year,

t = Time in years.

Let us convert our given rate in decimal form.

$2\%=\frac{2}{100}=0.02$

Upon substituting our given values in compound interest formula we will get,

$A=\$53,000(1+\frac{0.02}{1})^{1*4}$

$A=\$53,000(1+0.02)^{4}$

$A=\$53,000(1.02)^{4}$

$A=\$53,000*1.08243216$

$A=\$57368.90448\approx \$57,369$

Therefore, an amount of $57,369 will be in the account after 4 years.

3 0

2 years ago

ΔEFG ~ ΔLMN. Find LM.

Vika [28.1K]

EFG ~ LMN, if EF ~ LM, then whatever the number is for EF times whatever the others are multiplied by, you will get LM
for example:

FG (10) ~ MN (20)

if EF is (5), then LM is (10) (for you are multiplying by two.

Another example:

if FG is (100) ~ MN will be (200) (again for you are multiplying by two.

hope this helps

6 0

2 years ago

Read 2 more answers

Use a normal approximation to find the probability of the indicated number of voters. In this case assume that 150 eligible vote

alexdok [17]

The number of people who voted follows a binomial distribution with probability of having voted $p=0.22$ and $n=150$ subjects, which means the approximating normal distribution should have mean $np=33$ and standard deviation $\sqrt{np(1-p)}\approx5.07$ .

With the continuity correction, you have

$\mathbb P(X$

8 0

2 years ago

Given a graph for the transformation of f(x) in the format g(x) = f(x) + k, determine the k value. two parabolas open up with f

IgorLugansk [536]

Answer:

Step-by-step explanation:

5 0

2 years ago

Read 2 more answers

A random sample of 6 homes in Gainesville, Florida between 1800 and 2200 square feet had a mean of 212990 and a standard deviati

Andrej [43]

Answer:

The 95% confidence interval for the average price of a home in Gainesville of this size is between 183,772.5 square feet and 242,207.5 square feet.

Step-by-step explanation:

We have the standard deviation of the sample, so we use the students t-distribution.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 6 - 1 = 5

Now, we have to find a value of T, which is found looking at the t table, with 5 degrees of freedom(y-axis) and a confidence level of 0.95( $t_{95}$ ). So we have T = 2.015

The margin of error is:

M = T*s = 2.015*14500 = 29217.5.

In which s is the standard deviation of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 212990 - 29217.5 = 183,772.5 square feet

The upper end of the interval is the sample mean added to M. So it is 212990 + 29217.5 = 242,207.5 square feet

The 95% confidence interval for the average price of a home in Gainesville of this size is between 183,772.5 square feet and 242,207.5 square feet.

3 0

2 years ago