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2 years ago

5

Aul bought 10 reams of paper at the store for a total of $84 the tax on thepurchase was $4 what was the cost of each ream of pap

er?which equation could be used to represent this situation

1 answer:

yKpoI14uk [10]2 years ago

4 0

84+4/10
hope this helps

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An SRS of 350 high school seniors gained an average of x¯=21 points in their second attempt at the SAT Mathematics exam. Assume

Lynna [10]

Answer:

a) $21-2.58\frac{52}{\sqrt{350}}=13.83$

$21+2.58\frac{52}{\sqrt{350}}=28.17$

So on this case the 99% confidence interval would be given by (13.83;28.17)

b) $ME=2.58\frac{52}{\sqrt{350}}=7.17$

c) $ME=2.58\frac{52}{\sqrt{100}}=13.42$

d) D. Decreasing the sample size increases the margin of error, provided the confidence level and population standard deviation remain the same.

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".

Part a

$\bar X=21$ represent the sample mean

$\mu$ population mean (variable of interest)

$\sigma=52$ represent the population standard deviation

n=350 represent the sample size

99% confidence interval

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 0.99 or 99%, the value of $\alpha=0.01$ and $\alpha/2 =0.005$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.005,0,1)".And we see that $z_{\alpha/2}=2.58$

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

$21-2.58\frac{52}{\sqrt{350}}=13.83$

$21+2.58\frac{52}{\sqrt{350}}=28.17$

So on this case the 99% confidence interval would be given by (13.83;28.17)

Part b

The margin of error is given by:

$ME=2.58\frac{52}{\sqrt{350}}=7.17$

Part c

The margin of error is given by:

$ME=2.58\frac{52}{\sqrt{100}}=13.42$

Part d

As we can see when we reduce the sample size we increase the margin of error so the best option for this case is:

D. Decreasing the sample size increases the margin of error, provided the confidence level and population standard deviation remain the same.

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2 years ago

Which is the best buy?

gogolik [260]

Answer:

A

Step-by-step explanation:

work out price of each for one bottle

A) $12.60 ÷ 7 = $1.80

B) $10.98 ÷ 6 = $1.83

C) $18.10 ÷ 10 = $1.81

D) $16.38 ÷ 9 = $2.82

we can clearly see that A is the cheapest

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1 year ago

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What are the properties of the incenter of a triangle

Anit [1.1K]

<span>Located at intersection of the angle bisectors. See Triangle incenter definition</span>

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2 years ago

State which of the following sets of ordered pairs represent a function.

zalisa [80]

Answer:

Option (D) is correct.

Step-by-step explanation:

A function can be termed as a process from a set of x values to a set of possible y-values where each x-value relates to exactly one y-value.

In other words, a relation can only be a function there is no repetition of x-values. It means a relation can not have duplicated inputs.

Given the sets

Set A: (5,2), (4, 3), (3, 4), (2,5)

Set B: (-1,-6), (0, 2), (1, 2), (3, 6)

Set C: (2, 1), (4, 2), (2, 3), (8,4)

It is clear that sets A and B represent the function because, in these sets, each x-value relates to exactly one y-value. In other words, there are no duplicated inputs.

But, set C has duplicated inputs i.e. x = 2 is repeated twice, and a function can not have a repeated input.

Therefore, we conclude that set A and set B represent a function.

Thus, option (D) is correct.

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2 years ago

Find the value of x°

777dan777 [17]

Answer:

is it 82 degrees?

Step-by-step explanation:

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1 year ago