All categories

3 years ago

I need help on this one

Mathematics

2 answers:

miv72 [106K]3 years ago

8 0

Answer:

gfgfgfgfgfg

Step-by-step explanation:

serious [3.7K]3 years ago

6 0

Answer:

X= -4

Step-by-step explanation:

You might be interested in

Find a:27=6:11, find a

trasher [3.6K]

Answer:

a = 14.73

Step-by-step explanation:

This ratio can also be written like this:

$\frac{a}{27} = \frac{6}{11}$

Then you can cross multiply to get

11a = 6 x 27

11a = 162

Divide both sides by 11

11a / 11 = 162 / 11

a = 14.73

3 0

3 years ago

The law of exponent used in is _____

Lady bird [3.3K]

A is the answer I just did that on my usa test prep

5 0

2 years ago

Read 2 more answers

Katie and becca each bought a new book for $50 . Katie sold her book to the bookstore for 25% less than the original price. . Be

r-ruslan [8.4K]

$\text{Lets find the prices in which they sold their books for}\\\\\text{Katie:}\\\\\text{She sold the book for 25\% less than the original price, so multiply 50 by}\\\text{0.25 and subtract}\\\\50*0.25=12.5\\\\50-12.5=37.50\\\\\text{Becca:}\\\\\text{Becca sold the book for 40\% less than the original price, calculate how}\\\text{much she sold it for}\\\\50*0.40=20\\\\50-20=30\\\\$ $\text{We need to find how much more money Katie made than Becca, so subtract}\\\text{Becca's cost from Katie's cost}\\\\37.50-30=7.50\\\\\boxed{\text{Katie received \$7.50 more than Becca}}$

4 0

3 years ago

Read 2 more answers

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

Describe the relationship between the number of places a decimal point is moved to the left and the change in the value of the n

dimaraw [331]

For every decimal place you move a decimal through a number you can think of it as multiplying or dividing by ten.

take for example 1000.0
if you move the decimal to make this number 100.00 you divided it by ten
if you move the decimal again to make 10.000 you divided ten again

but, if you make the number bigger, say 10000. then you have multiplyed by ten.

3 0

3 years ago