If the area of a circle is 50.25 meters what is the radius

Students were asked to choose their favorite sport

r-ruslan [8.4K]

Answer:

5/9-1/9=4/9

Step-by-step explanation:

5/9 chose basketball or soccer. 1/9 chose basketball.

<h3>answer is 4/9</h3>

4 0

3 years ago

The residents of a city voted on whether to raise property taxes. The ratio of yes votes to no votes was

alekssr [168]

The formula would be set up as ratios (or fractions). The first ratio is 6:5, which in total is 11. There were 6 yes out of 11, so the fraction = 6/11.

The second fraction has a total of 5918, however you do not know the amount of yes votes, so the variable placeholder will be called "x".

The final formula would be:
6/11 = x/5918

You do cross multiplication and you get:
11x = 35508. You divide both sides, and you get x = 3228.

Because x is the placeholder for the amount of yes votes, and x = 3228, the amount of yes votes is 3228

6 0

4 years ago

Can someone explain to me how to turn a fraction into a decimal..? And a decimal into a fraction? Be specific please! I have a t

cricket20 [7]

To turn a decimal into a fraction move the decimal point two spots over (Ex: 0.34=34%). To turn a fraction into a decimal get the denominator to 100 by multiplying both the top and bottom by whatever number needed (must both be multiplied by the same number) or divide to top number into the bottom number of you can’t multiply.

8 0

4 years ago

23. A certain type of gasoline is supposed to have a mean octane rating of at least 90. Suppose measurements are taken on of 5 r

Nostrana [21]

Answer:

a) $p_v =P(Z$

b) Since $p_v$ we can reject the null hypothesis at the significance level given. So based on this we can commit type of Error I.

Because Type I error " is the rejection of a true null hypothesis".

c) $P(\bar X >90)=1-P(Z$

$1-P(Z$

d) For this case we need a z score that accumulates 0.02 of the area on the right tail and 0.98 on the left tail and this value is z=2.054

And we can use this formula:

$2.054=\frac{90-89}{\frac{0.8}{\sqrt{n}}}$

And if we solve for n we got:

$n = (\frac{2.054 *0.8}{1})^2=2.7 \approx 3$

Step-by-step explanation:

Previous concepts and data given

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".

We can calculate the sample mean and deviation with the following formulas:

$\bar X = \frac{\sum_{i=1}^n X_i}{n}$

$s=\sqrt{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}$

$\bar X=88.96$ represent the sample mean

$s=1.011$ represent the sample standard deviation

n=5 represent the sample selected

$\alpha$ significance level

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the mean is less than 90, the system of hypothesis would be:

Null hypothesis: $\mu \geq 90$

Alternative hypothesis: $\mu < 90$

If we analyze the size for the sample is < 30 and we don't know the population deviation so is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

$z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}$ (1)

z-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Calculate the statistic

We can replace in formula (1) the info given like this:

$z=\frac{88.96-90}{\frac{0.8}{\sqrt{5}}}=-2.907$

Part a

P-value

First we need to calculate the degrees of freedom given by:

$df=n-1=5-1 = 4$

Then since is a left tailed test the p value would be:

$p_v =P(Z$

Part b

Since $p_v$ we can reject the null hypothesis at the significance level given. So based on this we can commit type of Error I.

Because Type I error " is the rejection of a true null hypothesis".

Part c

We want this probability:

$P(\bar X$

The best way to solve this problem is using the normal standard distribution and the z score given by:

$z=\frac{x-\mu}{\frac{\sigma}{\sqrt{n}}}$

If we apply this formula to our probability we got this:

$P(\bar X >90)=1-P(Z$

$1-P(Z$

Part d

For this case we need a z score that accumulates 0.02 of the area on the right tail and 0.98 on the left tail and this value is z=2.054

And we can use this formula:

$2.054=\frac{90-89}{\frac{0.8}{\sqrt{n}}}$

And if we solve for n we got:

$n = (\frac{2.054 *0.8}{1})^2=2.7 \approx 3$

7 0

3 years ago

Question with last attempt is displayed for your review only

Alika [10]

Answer:

$43.13 = 5.25h + 9$

Step-by-step explanation:

Let's solve this by making an equation.

$9 for the helmet, and $5.25 per hour.

h will stand for hours, C will stand for Amanda's cost.

$C = 5.25h + 9$

Now, substitute in what we learned from the problem.

$43.13 = 5.25h + 9$

This is an equation you can use to solve for the hours.

3 0

3 years ago