What is the distance between points V(3, 3) and W(–2,

Help me out please:)

stich3 [128]

Answer:

the answer is

(8.5,13.5)

5 0

2 years ago

The label on a bottle of film developer states that the temperature, t, of the contents must be kept between 68° and 77° Fahrenh

skad [1K]

OK, so is this a question?

5 0

3 years ago

Read 2 more answers

A recent Gallup poll found that 36% of U.S. teens aged from 13 to 17 years old have a computer with [(6)] Internet access in the

In-s [12.5K]

Answer:

Step-by-step explanation:

a) The population parameter is the population proportion.

b) Confidence interval is written as

Sample proportion ± margin of error

Margin of error = z × √pq/n

Where

z represents the z score corresponding to the confidence level

p = sample proportion. It also means probability of success

q = probability of failure

q = 1 - p

p = x/n

Where

n represents the number of samples

x represents the number of success

From the information given,

n = 1028

p = 36/100 = 0.36

q = 1 - 0.36 = 0.64

To determine the z score, we subtract the confidence level from 100% to get α

α = 1 - 0.99 = 0.1

α/2 = 0.01/2 = 0.005

This is the area in each tail. Since we want the area in the middle, it becomes

1 - 0.05 = 0.995

The z score corresponding to the area on the z table is 2.58. Thus, confidence level of 99% is 2.58

Therefore, the 99% confidence interval is

0.36 ± 2.58 × √(0.36)(0.64)/1028

The lower limit of the confidence interval is

0.36 - 0.039 = 0.321

The upper limit of the confidence interval is

0.36 + 0.039 = 0.399

Therefore, with 99% confidence interval, the proportion of U.S. teens aged from 13 to 17 years old that have a computer with Internet access in their rooms is between 0.321 and 0.399

c) for a margin of error of 1%, that is 1/100 = 0.01, then

0.01 = 2.58 × √(0.36)(0.64)/n

0.01/2.58 = √0.2304/n

0.00387596899 = √0.2304/n

Square both sides

0.00001502314 = 0.2304/n

n = 0.2304/0.00001502314

n = 15336

5 0

3 years ago

SAT scores are normed so that, in any year, the mean of the verbal or math test should be 500 and the standard deviation 100. as

vovangra [49]

Answer:

a) $P(X>625)=P(\frac{X-\mu}{\sigma}>\frac{625-\mu}{\sigma})=P(Z>\frac{625-500}{100})=P(Z>1.25)$

$P(Z>1.25)=1-P(Z$

b) $P(400$

$P(-1$

c) $z=-0.842$

And if we solve for a we got

$a=500 -0.842*100=415.8$

So the value of height that separates the bottom 20% of data from the top 80% is 415.8.

Step-by-step explanation:

Previous concepts

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 Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

Part a

Let X the random variable that represent the SAT scores of a population, and for this case we know the distribution for X is given by:

$X \sim N(500,100)$

Where $\mu=500$ and $\sigma=100$

We are interested on this probability

$P(X>625)$

And the best way to solve this problem is using the normal standard distribution and the z score given by:

$z=\frac{x-\mu}{\sigma}$

If we apply this formula to our probability we got this:

$P(X>625)=P(\frac{X-\mu}{\sigma}>\frac{625-\mu}{\sigma})=P(Z>\frac{625-500}{100})=P(Z>1.25)$

And we can find this probability using the complement rule and with the normal standard table or excel:

$P(Z>1.25)=1-P(Z$

Part b

We are interested on this probability

$P(400$

And the best way to solve this problem is using the normal standard distribution and the z score given by:

$z=\frac{x-\mu}{\sigma}$

If we apply this formula to our probability we got this:

$P(400$

And we can find this probability with this difference:

$P(-1$

And in order to find these probabilities we can find tables for the normal standard distribution, excel or a calculator.

$P(-1$

Part c

For this part we want to find a value a, such that we satisfy this condition:

$P(X>a)=0.8$ (a)

$P(X$ (b)

Both conditions are equivalent on this case. We can use the z score again in order to find the value a.

As we can see on the figure attached the z value that satisfy the condition with 0.2 of the area on the left and 0.8 of the area on the right it's z=-0.842. On this case P(Z<-0.842)=0.2 and P(Z>-0.842)=0.8

If we use condition (b) from previous we have this:

$P(X$

$P(z$

But we know which value of z satisfy the previous equation so then we can do this:

$z=-0.842$

And if we solve for a we got

$a=500 -0.842*100=415.8$

So the value of height that separates the bottom 20% of data from the top 80% is 415.8.

8 0

2 years ago

Need help on math You have a meal at a restaurant. The sale tax is 8% . You leave a tip for the waitress that is 20% of the pret

DerKrebs [107]

Answer: $18

Step-by-step explanation:

Let x= Pretax price of the meal.

Given: Sales tax = 8%

Tip percent = 20%

As per given ,

Amount spent = ( Pretax price) + (Sales tax ) of (Pretax price) + (Tip percent)of (Pretax price)

= x+ 8% of x + 20% of x

= x +0.08+0.20x

= 1.28x

∵ Amount spent = $23.04

So,

$1.28x=23.04\\\\\Rightarrow\ x=\dfrac{23.04}{1.28}\\\\\Rightarrow\ x=18$

Hence, the pretax price of the meal= $18.

4 0

3 years ago

What is the distance between points V(3, 3) and W(–2, –3)?