2x + 3y = 6<br> Solve for y

Francine ran 3 1/2 laps around the circular track in the school gym. The track has a diameter of 1/2 miles. About how far does F

Juliette [100K]

Answer:

Francine run 5.495 miles

Step-by-step explanation:

Given :

Francine ran $3\frac{1}{2}$ laps around the circular track in the school gym.

The track has a diameter of 1/2 miles.

To Find : About how far does Francine run?

Solution :

First we need to calculate the perimeter of circular track :

Perimeter of circle : $2\pi r$

Since we are given the diameter = 1/2 miles = 0.5 miles

So, Radius will be (Diameter/2) = 0.5/2 = 0.25 miles

So, The perimeter will be:

$2\pi *0.25$

$0.5\pi$

Since $\pi =3.14$

⇒ $0.5*3.14$

⇒ $1.57$

Thus the circular track is of 1.57 miles .

Since she ran $3\frac{1}{2}$ = 7/2=3.5 laps

1 lap = 1.57 miles

So, 3.5 laps = 1.57*3.5 =5.495 miles .

Hence , Francine run 5.495 miles

6 0

3 years ago

Which of the following describes the quotient of 4 and -28? A) The quotient is undefined. B) The quotient is an integer. C) The

DanielleElmas [232]

Answer:

-1/7

Step-by-step explanation:

Divide the first expression by the second expression.

6 0

3 years ago

In a random sample of 80 teenagers, the average number of texts handled in a day is 50. The 96% confidence interval for the mean

Nastasia [14]

Answer:

a) $\bar X =\frac{46+54}{2}=50$

And the margin of error is given by:

$ME= \frac{54-46}{2}= 4$

The confidence level is 0.96 and the significance level is $\alpha=1-0.96=0.04$ and the value of $\alpha/2 =0.02$ and the margin of error is given by:

$ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$

We can calculate the critical value and we got:

$z_{\alpha/2} = 2.05$

And if we solve for the deviation like this:

$\sigma = ME * \frac{\sqrt{n}}{z_{\alpha/2}}$

And replacing we got:

$\sigma =4 *\frac{\sqrt{80}}{2.05} =17.45$

b) $ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}=2.05 *\frac{17.45}{\sqrt{160}}=2.828$

And as we can see that the margin of error would be lower than the original value of 4, the margin of error would be reduced by a factor $\sqrt{2}$

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".

$\bar X$ represent the sample mean

$\mu$ population mean (variable of interest)

$\sigma$ represent the population standard deviation

n=80 represent the sample size

Solution to the problem

Part a

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

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

For this case we can calculate the mean like this:

$\bar X =\frac{46+54}{2}=50$

And the margin of error is given by:

$ME= \frac{54-46}{2}= 4$

The confidence level is 0.96 and the significance level is $\alpha=1-0.96=0.04$ and the value of $\alpha/2 =0.02$ and the margin of error is given by:

$ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$

We can calculate the critical value and we got:

$z_{\alpha/2} = 2.05$

And if we solve for the deviation like this:

$\sigma = ME * \frac{\sqrt{n}}{z_{\alpha/2}}$

And replacing we got:

$\sigma =4 *\frac{\sqrt{80}}{2.05} =17.45$

Part b

For this case is the sample size is doubled the margin of error would be:

$ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}=2.05 *\frac{17.45}{\sqrt{160}}=2.828$

And as we can see that the margin of error would be lower than the original value of 4, the margin of error would be reduced by a factor $\sqrt{2}$

5 0

3 years ago

Manny walked a total of 3 miles. what is The reference point used to calculate the total distance that he walked was the same as

Firlakuza [10]

B. On a circular nature trail.
As Manny ended up at the same point from where he started after walking 3 miles, he walked in a circle.

8 0

3 years ago

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Can someone help with this true or false math

matrenka [14]

the answer is false

isididididododidid

3 0

2 years ago

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2x + 3y = 6 Solve for y