2 x 6/7 SEND HELP!!!!!!!!!!!

Lee washes the outsides of houses. It takes him 40 minutes to power wash a one-story home, and he uses 180 gallons of water. Pow

Grace [21]

Answer:

d

Step-by-step explanation:

TOOK THE TEST

6 0

2 years ago

Question 3(Multiple Choice Worth 5 points)

Zanzabum

Answer:

0.3

Step-by-step explanation:

just divide on a calculator 3/9 and u get 0.3

4 0

3 years ago

Help a man out, ive been stuck on this for a while.

forsale [732]

Answer:

1. true - dilating figures does not change their angle measure

2. true - dilating figures does not change the orientation, so AD would still be on a horizontal line parallel to its current position

6 0

3 years ago

An SRS of 350 high school seniors gained an average of x¯=21 points in their second attempt at the SAT Mathematics exam. Assume

Lynna [10]

Answer:

a) $21-2.58\frac{52}{\sqrt{350}}=13.83$

$21+2.58\frac{52}{\sqrt{350}}=28.17$

So on this case the 99% confidence interval would be given by (13.83;28.17)

b) $ME=2.58\frac{52}{\sqrt{350}}=7.17$

c) $ME=2.58\frac{52}{\sqrt{100}}=13.42$

d) D. Decreasing the sample size increases the margin of error, provided the confidence level and population standard deviation remain the same.

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".

Part a

$\bar X=21$ represent the sample mean

$\mu$ population mean (variable of interest)

$\sigma=52$ represent the population standard deviation

n=350 represent the sample size

99% confidence interval

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

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

Since the Confidence is 0.99 or 99%, the value of $\alpha=0.01$ and $\alpha/2 =0.005$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.005,0,1)".And we see that $z_{\alpha/2}=2.58$

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

$21-2.58\frac{52}{\sqrt{350}}=13.83$

$21+2.58\frac{52}{\sqrt{350}}=28.17$

So on this case the 99% confidence interval would be given by (13.83;28.17)

Part b

The margin of error is given by:

$ME=2.58\frac{52}{\sqrt{350}}=7.17$

Part c

The margin of error is given by:

$ME=2.58\frac{52}{\sqrt{100}}=13.42$

Part d

As we can see when we reduce the sample size we increase the margin of error so the best option for this case is:

D. Decreasing the sample size increases the margin of error, provided the confidence level and population standard deviation remain the same.

6 0

2 years ago

Unit rate How many cents would you earn per minute? Show work ASAP

Yanka [14]

So, it depends. Imma give you two answers, all of which are the same at the end. They just have different ways to do it.

1. So, it's $9 per hour, or $9 per 60 min 
You can write a ratio: 9/60 = n/1 
In this case you have to divide 9 by 60 cause
60/60 = 1 
And n=0.15 
Answer: you earn 15 cents per min.

2.$9 = 900 cents 
900 cents divided by 60 minutes = 15 cents in a minute.

Hope this helps love!! :)

8 0

3 years ago

Read 2 more answers