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3 years ago

Anna is saving to buy some souvenirs on a family vacation. She has already saved $125, and she saves another $2 from her

Mathematics

2 answers:

lorasvet [3.4K]3 years ago

8 0

Answer: y=125+2x or y=2x+125

Step-by-step explanation:

First, create the equation that models the situation.

The amount Anne already saves is the intial value, ory-intercept, which in this case is 125. She adds 2 to her savings everyday/ so the rate of change, or slope, is 2.

y=125+2x or y=2x+125

plot the y intercept then plot a second point using the slope of 2 or 2/1 draw a line that connects the y intercept and the other point.

FinnZ [79.3K]3 years ago

6 0

We can assume that the y-intercept for this equation is 125, because that would be how much Anna already has saved before she begins saving money from her allowance. Then, we know that Anna adds $2 to her savings each day from the problem, so we know that the slope will be positive 2 then.

Equation:

y = 2x + 125

Graph:

Attached below

Hope this helps!! :)

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Step-by-step explanation:

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Answer:

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Step-by-step explanation:

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2 years ago

the perimeter of a rectangle is 34 units. it’s width is 6.5 units. write the equation to determine the length of the rectangle

zubka84 [21]

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Step-by-step explanation:

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2 years ago

A science teacher has a supply of 5% hydrochloric acid and a supply of 65% hydrochloric acid(HC1). How much of each solution sho

Sphinxa [80]

Assume that the amount needed from the 5% solution is x and that the amount needed from the 65% solution is y.

We are given that, the final solution should be 42 ml, this means that:
x + y = 42 ...........> equation I
This can also be written as:
x = 42-y .......> equation II

We are also given that the final concentration should be 45%, this means that:
5% x + 65% y = 45% (x+y)
0.05x + 0.65y = 0.45(x+y)

We have x+y = 42 from equation I, therefore:
0.05x + 0.65y = 0.45(42)
0.05x + 0.65y = 18.9 .........> equation III

Substitute with equation II in equation III as follows:
0.05x + 0.65y = 18.9
0.05(42-y) + 0.65y = 18.9
2.1 - 0.05y + 0.65y = 18.9
0.6y = 18.9 - 2.1
0.6y = 16.8
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Substitute with y in equation II to get x as follows:
x = 42-y
x = 42 - 28
x = 14 ml

Based on the above calculations:
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amount of 65% solution = y = 28 ml
The correct choice is:
The teacher will need 14 mL of the 5% solution and 28 mL of the 65% solution.

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3 years ago

A realtor would like to create a 95% confidence interval for the average price of a house in Franklin County, Ohio. To accomplis

VMariaS [17]

Answer:

$320128-1.96\frac{50324}{\sqrt{529}}=315839.52$

$320128+1.96\frac{50324}{\sqrt{529}}=324416.48$

So on this case the 95% confidence interval would be given by (315839.52;324416.48)

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X=320128$ represent the sample mean

$\mu$ population mean (variable of interest)

$\sigma=50324$ represent the population standard deviation

n=529 represent the sample size

Solution to the problem

The confidence interval for the mean is given by the following formula:

$\bar X \pm z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (1)

Since the Confidence is 0.95 or 95%, the value of $\alpha=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.025,0,1)".And we see that $z_{\alpha/2}=1.96$

Now we have everything in order to replace into formula (1):

$320128-1.96\frac{50324}{\sqrt{529}}=315839.52$

$320128+1.96\frac{50324}{\sqrt{529}}=324416.48$

So on this case the 95% confidence interval would be given by (315839.52;324416.48)

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3 years ago