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3 years ago

12

"You and your friend go to dinner and your total bill is $30. You are both part of the rewards club and have coupons. Your coupo

n is for 10% off the total bill. Your friends coupon is for 5.00 off the bill.
Which coupon should you use to save the most money?
A- The 5% coupon saves you the most.
B- The 10% off coupon saves you the most.

1 answer:

galben [10]3 years ago

7 0

Answer:

30+30=11

Step-by-step explanation:

so bye

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Tim measures the length of four grasshoppers in his backyard: 5/4 cm, 7/4 cm, 9/4 cm, and 3/4 cm. What is the average length.

katrin [286]

Answer:6

Step-by-step explanation: add up all the fractions. The answer will be 24/4. Divide 24/4 equals 6.

6 0

3 years ago

A simple random sample of items resulted in a sample mean of . The population standard deviation is . a. Compute the confidence

Varvara68 [4.7K]

Answer:

(a): The 95% confidence interval is (46.4, 53.6)

(b): The 95% confidence interval is (47.9, 52.1)

(c): Larger sample gives a smaller margin of error.

Step-by-step explanation:

Given

$n = 30$ -- sample size

$\bar x = 50$ -- sample mean

$\sigma = 10$ --- sample standard deviation

Solving (a): The confidence interval of the population mean

Calculate the standard error

$\sigma_x = \frac{\sigma}{\sqrt n}$

$\sigma_x = \frac{10}{\sqrt {30}}$

$\sigma_x = \frac{10}{5.478}$

$\sigma_x = 1.825$

The 95% confidence interval for the z value is:

$z = 1.960$

Calculate margin of error (E)

$E = z * \sigma_x$

$E = 1.960 * 1.825$

$E = 3.577$

The confidence bound is:

$Lower = \bar x - E$

$Lower = 50 - 3.577$

$Lower = 46.423$

$Lower = 46.4$ --- approximated

$Upper = \bar x + E$

$Upper = 50 + 3.577$

$Upper = 53.577$

$Upper = 53.6$ --- approximated

<em>So, the 95% confidence interval is (46.4, 53.6)</em>

Solving (b): The confidence interval of the population mean if mean = 90

First, calculate the standard error of the mean

$\sigma_x = \frac{\sigma}{\sqrt n}$

$\sigma_x = \frac{10}{\sqrt {90}}$

$\sigma_x = \frac{10}{9.49}$

$\sigma_x = 1.054$

The 95% confidence interval for the z value is:

$z = 1.960$

Calculate margin of error (E)

$E = z * \sigma_x$

$E = 1.960 * 1.054$

$E = 2.06584$

The confidence bound is:

$Lower = \bar x - E$

$Lower = 50 - 2.06584$

$Lower = 47.93416$

$Lower = 47.9$ --- approximated

$Upper = \bar x + E$

$Upper = 50 + 2.06584$

$Upper = 52.06584$

$Upper = 52.1$ --- approximated

<em>So, the 95% confidence interval is (47.9, 52.1)</em>

Solving (c): Effect of larger sample size on margin of error

In (a), we have:

$n = 30$ $E = 3.577$

In (b), we have:

$n = 90$ $E = 2.06584$

<em>Notice that the margin of error decreases when the sample size increases.</em>

4 0

3 years ago

The surface area of a sphere is 576pi square units. Which choice represents the volume of the sphere?

Leona [35]

Answer:

$\large\boxed{V=2304\pi}$

Step-by-step explanation:

The formula of a surface area of a sphere:

$S.A.=4\pi R^2$

R - radius

We have

$S.A.=576\pi$

Substitute and solve for R:

$4\pi R^2=576\pi$ <em>divide both sides by π</em>

$4R^2=576$ <em>divide both sides by 4</em>

$R^2=144\to R=\sqrt{144}\\\\R=12$

The formula of a volume of a sphere:

$V+\dfrac{4}{3}\pi R^3$

Substitute:

$V=\dfrac{4}{3}\pi(12^3)=\dfrac{4}{3}\pi(1728)=(4)\pi(576)=2304\pi$

3 0

3 years ago

Arrange the steps to solve the equation square root x+3 - square root 2x-1=-2

stiv31 [10]

Answer:x=31.4919

Step-by-step explanation:

Step1:isolate a square root on the left hand side√x+3=√2x-1-2

Step2:eliminate the radicals on the left hand side

Raise both sides to the second power

√x+3)^2=(√2x-1-2)^2

After squaring

x+3=2x-1+4-4-4√2x-1

Step3:get the remaining radicals by itself

x+3=2x-1+4-4√2x-1

Isolate radical on the left hand side

4√2x-1=-x-3+2x-1+4

4√2x-1=x

Step4:eliminate the radicals on the left hand side

Raise both side to the second power

(4√2x-1)^2=x^2

After squaring

32x-16=x^2

Step 5:solve the quadratic equation

x^2-32x-16

This equation has two real roots

x1=32+√960/2=31.4919

x2=32-√960/2=0.5081

Step6:check that the first solution is correct

Put in 31.4919 for x

√31.4919+3=√2•31.4919-1-2

√34.492=5.873

x=31.4919

Step7:check that the second solution is correct

√x+3=√2x-1-2

Put in 0.5081 for x

√0.5081+3=√2•0.5081-1-2

√3.508=-1.873

1.873#-1.873

One solution was found

x=31.4919

6 0

3 years ago

PLS help me fast!!!!

Radda [10]

Answer:

The correct option is 1.

Step-by-step explanation:

It is given that the box plot shows the number of books sold each day at a store for 80 days.

A box plot is drawn with end points at 0 and 16. It means minimum value is 0 and maximum is 16.

The box extends from 2 to 12. It means first quartile is 2 and the third quartile is 12. A vertical line is drawn inside the box at 7, it means median is 7.

He have to find the number of days in which the bookstore sell 2 to 12 books.

2 is first quartile and 12 is third quartile, we know that

$Q_1=25\%$

$Q_3=75\%$

$Q_3-Q_1=75\%-25\%=50\%$

The data lies between Q₁ and Q₃ is 50% of the data.

$80\times \frac{50}{100}=40$

The bookstore sell 2 to 12 books in 40 days.

Therefore, the correct option is 1.

5 0

3 years ago

Read 2 more answers