Ask question

Ask question

All categories

3 years ago

14

A customer paid 5$ in tax. His tax rate was 5%. Fin the dollar amount of his purchase

1 answer:

Burka [1]3 years ago

5 0

Hey there!

Let's create an equation for this scenario.

0.05x=5

This equation shows that the $5 is equal to 0.05% (sales tax) of the cost paid for the item.

let's solve by dividing both sides by 0.05x.

x=100

Therefore, his purchase costed $100 before sales tax.

I hope this helps!

You might be interested in

Amy has to write a paper for school that has more than 2,878 words. She has already written 1,037 words and writes at a rate

densk [106]

Answer:

C

Step-by-step explanation:

263x = words per day

add on 1,037 because she already wrote them

263x + 1,037 > 2,878

7 0

3 years ago

What is the area of the triangle in the coordinate plane?

katovenus [111]

To solve for the area of a triangle you use the formula A=b*h/2. The base for this triangle is 4 and the height is 8. Take 4*8 which is 32 and divide that answer in half to get 16 which is your answer.

6 0

3 years ago

Read 2 more answers

4. A random variable X has a mean of 10 and a standard deviation of 3. If 2 is added to each value of X, what will the new mean

Ede4ka [16]

Adding 2 to each value of the random variable $X$ makes a new random variable $X+2$ . Its mean would be

$E[X+2]=E[X]+E[2]=E[X]+2$

since expectation is linear, and the expected value of a constant is that constant. $E[X]$ is the mean of $X$ , so the new mean would be

$E[X+2]=10+2=12$

The variance of a random variable $X$ is

$V[X]=E[X^2]-E[X]^2$

so the variance of $X+2$ would be

$V[X+2]=E[(X+2)^2]-E[X+2]^2$

We already know $E[X+2]=12$ , so simplifying above, we get

$V[X+2]=E[X^2+4X+4]-12^2$

$V[X+2]=E[X^2]+4E[X]+4-12^2$

$V[X+2]=(V[X]+E[X]^2)+4E[X]-140$

Standard deviation is the square root of variance, so $V[X]=3^2=9$ .

$\implies V[X+2]=(9+10^2)+4(10)-140=9$

so the standard deviation remains unchanged at 3.

NB: More generally, the variance of $aX+b$ for $a,b\in\mathbb R$ is

$V[aX+b]=a^2V[X]+b^2V[1]$

but the variance of a constant is 0. In this case, $a=1$ , so we're left with $V[X+2]=V[X]$ , as expected.

5 0

3 years ago

Simplify 4(x+2)-3(7+y)

strojnjashka [21]

Use distributive property <em>a(b + c) = ab + ac</em>

4(x + 2) - 3(7 + y) = (4)(x) + (4)(2) + (-3)(7) + (-3)(y)

= 4x + 8 - 21 - 3y = 4x - 3y - 13

4 0

3 years ago

HELP! Please! HELP! Please see attachment to see the problem

romanna [79]

The angle is equal, set x+40 = 60 solve for x, which is 20

4 0

3 years ago

Read 2 more answers