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2 years ago

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Rayhana has a coupon for 15% off a single item at a store. If the item has a regular price of p dollars, then the sale price can

be represented by p – 0.15p. Which expression is equivalent?

1 answer:

levacccp [35]2 years ago

8 0

Answer: D.

Step-by-step explanation:

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3. Using the sample size of 800 and the proportion 0.47, calculate the margin of error associated with the estimate of the propo

salantis [7]

Answer:

$ME=1.96\sqrt{\frac{0.47 (1-0.47)}{800}}=0.0346$

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".

The population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{p(1-p)}{n}})$

Solution to the problem

We assume for this case a confidence level of 95%. In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 95% of confidence, our significance level would be given by $\alpha=1-0.95=0.05$ and $\alpha/2 =0.025$ . And the critical value would be given by:

$z_{\alpha/2}=-1.96, z_{1-\alpha/2}=1.96$

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

$\hat p \pm z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$

The margin of error for the proportion interval is given by this formula:

$ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$ (a)

And if we replace the values obtained we got this:

$ME=1.96\sqrt{\frac{0.47 (1-0.47)}{800}}=0.0346$

6 0

2 years ago

The change in the value of an account when given to the nearest dollar?

devlian [24]

What changes may occur if the given dollar will be rounded off to its nearest value.
<span>There will only be 2 chances, the dollar will become smaller or bigger. Why? </span>
Because in mathematical rules of rounding off numbers:
number below 5 will be round down and 5 and up will be rounded up.
For example:
You have a bill of $6.79 since the number next to the decimal point in the right is 7, it will be rounded up to $7.
<span>But if your bill is $6.25, it will be rounded down to $6.00
</span>
I got this from a different brainy member

7 0

3 years ago

Factorise 10x²+19x+6<br><br> Show working out please.

stepladder [879]

Answer:

(2x+3)(5x+2)

Step-by-step explanation:

10x²+19x+6

multiply to get 60

add to get 19

10x²+19x+6

(10x²+15x)(+4x+6)

factorise:

10x²+15x

5x(2x+3)

4x+6

2(2x+3)

(2x+3)(5x+2)

8 0

2 years ago

PLEASE HELP TIMED TEST!!!! I WILL REPORT YOU IF YOU GIVE ME A LINK!!

Elenna [48]

Answer:

x=40

Step-by-step explanation:

you have to get a answer of 60

(40)+20=60

and 2(40)-20=60

5 0

2 years ago

Mr. Nicholson accepts a job that pays an annual salary of $60,000. In his employment contract, he is given the option of choosin

Andre45 [30]

Answer:

1. Arithmetic: Add 3,500

The annual raise of 3,500 means add 3,500 to the previous year's salary

60,000 + 3,500 = 63,500

63,500 + 3,500 = 67,000

67,000 + 3,500 = 70,500

70,500 + 3,500 = 74,000

74,000 + 3,500 = 77,500

Geometric: Multiply by 1.05

The annual raise by 5% of his current salary means multiply by 1.05.

60,000 x 1.05 = 63,000

63,000 x 1.05 = 66,150

66,150 x 1.05 = 69,457.50

69,457.50 x 1.05 = 72,930.38 rounded

72,930.375 x 1.05 = 76,576.89

The first sequence is arithmetic because we add the same number (3,500) to the preceding term. The second sequence is geometric because we multiply the preceding term by the same number always (1.05.)

2a. Arithmetic - New salary is $3,500 greater each year than last year's salary

S = 60,000 + 3500(n-1)

Geometric - New salary is 5% more each year than last year's salary

60,000 + (1.05)^(n-1)

2b. Arithmetic Earnings over 3 years

60,000 + 63,500 + 67,000 = 190,500

Geometric Earnings over 3 years

60,000 + 63,000 + 66,150 = 189,150

There is a 1,000 dollar difference. In this case, the arithmetic increase of 3,500 dollars would be better for Mr. Nicholson. 1,000 dollars may or may not be considered a big difference. In my opinion, I'd say there is a slight difference between the two

3.Arithmetic

a(9) = 3,500 + a(9-1)

a(9) = 3,500 + 89,000

a(9) = 92,500

Geometric

a(9) = 1.05 x a(9-1)

a(9) = 1.05 x 84,425.90

a(9) = 88,647.20

4. In this case, both the 3 year and 9 year time frames favor the arithmetic increase of $3,500. At 3 years, he would have 190,500 compared to the geometric salary of 189,150. However, this is a small difference. If he is going to be at the company for 9 years, then definitely he should choose the first opportunity. 92,500 is significantly more money than 88,647.20. So, longer time frames only make the first opportunity, which is better to begin with, shine even more.

Step-by-step explanation:

Pls brain list

8 0

2 years ago