Jackie bought 100 stamps. Each stamp cost $0.37. How much did Jackie spend?

2/3 + (-1/3) = ?????

amm1812

Answer: (+) 1/3

Step-by-step explanation: 2/3 + -1/3 is basically subtracting 1/3 from 2/3 so, 2/3 - 1/3 = 1/3.

6 0

3 years ago

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Maliah goes to an electronics store. Let y represent the price of a laptop and let z represent the price of a television. The eq

scZoUnD [109]

Answer:

hi

Step-by-step explanation:

8 0

3 years ago

Your state is considering raising the legal age for consumption of alcoholic beverages to 21 years old. How large a sample size

julsineya [31]

Answer:

$n=\frac{0.5(1-0.5)}{(\frac{0.01}{2.58})^2}=16641$

And rounded up we have that n=16641

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

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 99% of confidence, our significance level would be given by $\alpha=1-0.99=0.01$ and $\alpha/2 =0.005$ . And the critical value would be given by:

$z_{\alpha/2}=-2.58, t_{1-\alpha/2}=2.58$

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 $ME =\pm 0.01$ 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)

For this case we can use as estimator for the proportion $\hat p =0.5$ , since we don't have any other previous info. And replacing into equation (b) the values from part a we got:

$n=\frac{0.5(1-0.5)}{(\frac{0.01}{2.58})^2}=16641$

And rounded up we have that n=16641

8 0

3 years ago

Several friends bought flowers to make table centerpieces. write the ratios of purple flowers to white flowers for each friend.

Zina [86]

The ratio for Rowan = 4:1.

The ratio for Marcia = 10:1.

The ratio for Jillian = 5:1.

The ratio for Lulua = 6:1.

The smallest ratio among these for purple to white flowers is for Rowan, that is, 4:1.

Ratios are fractions in the simplest form representing the relationship between two quantities.

The ratio of purple to white flowers for each friend can be shown as:-

Rowan:

The number of purple flowers = 8

The number of white flowers = 2

Thus, the fraction of purple to white flowers = 8/2 = 4/1.

Thus, the ratio for Rowan = 4:1.

Marcia:

The number of purple flowers = 10

The number of white flowers = 1

Thus, the fraction of purple to white flowers = 10/1.

Thus, the ratio for Marcia = 10:1.

Jillian:

The number of purple flowers = 10

The number of white flowers = 2

Thus, the fraction of purple to white flowers = 10/2 = 5/1.

Thus, the ratio for Jillian = 5:1.

Lulua:

The number of purple flowers = 18

The number of white flowers = 3

Thus, the fraction of purple to white flowers = 18/3 = 6/1.

Thus, the ratio for Lulua = 6:1.

The smallest ratio among these for purple to white flowers is for Rowan, that is, 4:1.

Learn more about ratios at

brainly.com/question/3989414

#SPJ4

4 0

2 years ago

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Elza [17]

So the answer is 30 packages but I did 25 times 20 = 500 and then 25 times 10 = 250
So. 30 = 750

6 0

3 years ago

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