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3 years ago

PLEASE ANSWER What is a ratio?

1 answer:

7 0

A ratio is the quantitative relation between two amounts showing the number of times one value contains or is contained within the other.

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Zaire is making granola bars. For one batch of bars, the recipe calls for 1 2/3 cups of rolled oats and ½ cup of raisins. What i

Daniel [21]

Answer:

13/6

No explanation sorry :(

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2 years ago

One inch of rain on a square foot of land weights 5.2 pounds. About how many ghallons of rain are there? round your answer to th

mrs_skeptik [129]

Answer: 0.60 gallon

Step-by-step explanation:

There are 12pounds in a standard US gallon.

12pounds= 1 gallon

5.2 pounds=?

5.2/12 × 1 gallon

0.624 gallon

Rounding to the nearest tenth =0.60

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3 years ago

My brother wants to estimate the proportion of Canadians who own their house.What sample size should be obtained if he wants the

AVprozaik [17]

Answer:

a) $n=\frac{0.675(1-0.675)}{(\frac{0.02}{1.64})^2}=1475.07$

And rounded up we have that n=1476

b) $n=\frac{0.5(1-0.5)}{(\frac{0.02}{1.64})^2}=1681$

And rounded up we have that n=1681

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

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

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)

If solve n from equation (a) we got:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$ (b)

Part a

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 90% of confidence, our significance level would be given by $\alpha=1-0.9=0.1$ and $\alpha/2 =0.05$ . And the critical value would be given by:

$z_{\alpha/2}=\pm 1.64$

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 on this case we have that $ME =\pm 0.02$ and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$ (b)

And replacing into equation (b) the values from part a we got:

$n=\frac{0.675(1-0.675)}{(\frac{0.02}{1.64})^2}=1475.07$

And rounded up we have that n=1476

Part b

For this case since we don't have a prior estimate we can use $\hat p =0.5$

$n=\frac{0.5(1-0.5)}{(\frac{0.02}{1.64})^2}=1681$

And rounded up we have that n=1681

8 0

3 years ago

Decide if each expression is equivalent to 2^6 or 4^4

11Alexandr11 [23.1K]

$\huge\text{Hey there!}$

$\mathsf{2^6 = 2\times2\times2\times2\times2\times2}\\\mathsf{2\times2\times2\times2\times2\times2}\\\mathsf{2\times2=4}\\\mathsf{4\times4\times4}\\\mathsf{4\times4=16}\\\large\mathsf{16\times4=64}\\\mathsf{2^6 = \bf{64}}$

$\mathsf{4^4=4\times4\times4\times4}\\\mathsf{4\times4\times4\times4}\\\mathsf{4\times4=16}\\\mathsf{16\times16}\\\mathsf{16\times16=256}\\\mathsf{4^4=\bf{256}}$