-5x+5y=10<br> 3x-3y= -10

AYYYYYYYYYYYYYYYYY FREEEEEE BRAINLY POINTSSSSS!!!!!!!! ┗|｀O′|┛w(ﾟДﾟ)w WOOOOOOOOOOOO FREEE POINTS UWU 34+ 28 ÷ 3 × 4 (10)

Yakvenalex [24]

Answer:

woah thx

Step-by-step explanation:

71.3

7 0

3 years ago

Read 2 more answers

A store sold 50 copies of a magazine for $150. Each copy of the magazine costs the same. Which equation and set of ordered pairs

snow_tiger [21]

It is 3 copies per magazine

4 0

4 years ago

In a certain apartment building the ratio of tenants to cars is 3:5. if there are 30 tenants, how many cars are there?

Fittoniya [83]

Answer:

I want to say 50 cars

Step-by-step explanation:

If i am correct, there are more cars than people overall:

tenants to cars

3:5

so when you have 30 tenants you can multiply the cars by ten because that is what you did on the other side.

6 0

4 years ago

Suppose the method of tree ring dating gave the following dates A.D. for an archaeological excavation site. Please show your wor

natita [175]

Answer:

a) $\bar X=\frac{1245+1245+1321+1191+1295+1330+1239+1250+1228}{9}= 1260.444$

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

And if we replace we got:

$s = 45.580$

c) For this case since the sampel size is n=9 <30 we can use the t distribution in order to find the confidence interval.

d) $1260.444-2.306 \frac{45.580}{\sqrt{9}}= 1225.408$

$1260.444+2.306 \frac{45.580}{\sqrt{9}}= 1295.480$

Step-by-step explanation:

For this case we ave the following data:

1245 1245 1321 1191 1295 1330 1239 1250 1228

Part a

We can calculate the sample mean with the following formula:

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

And if we replace we got:

$\bar X= \frac{1245+1245+1321+1191+1295+1330+1239+1250+1228}{9}= 1260.444$

Part b

For this case we can use the following formula in order to find the sample standard deviation:

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

And if we replace we got:

$s = 45.580$

Part c

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".

For this case since the sampel size is n=9 <30 we can use the t distribution in order to find the confidence interval.

Part d

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

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

We need to find the degrees of freedom given by:

$df = n-1 = 9-1=8$

Since the Confidence is 0.95 or 95%, the value of $\alpha=1-0.95=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.025,8)".And we see that $t_{\alpha/2}=2.306$

Now we have everything in order to replace into formula (1):

$1260.444-2.306 \frac{45.580}{\sqrt{9}}= 1225.408$

$1260.444+2.306 \frac{45.580}{\sqrt{9}}= 1295.480$

8 0

4 years ago

A 16-foot piece of string is cut into two pieces so that the longer piece is 1 foot longer than twice the shorter piece. If the

vlada-n [284]

Longer piece=2x+1
shorter piece=x
2x+1+x=16
3x=15
x=5
The shorter piece is 5ft and the longer is 11ft

Did that help any?

6 0

3 years ago

-5x+5y=10 3x-3y= -10