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3 years ago

HELP! ITS ABOUT SURVEYSSS EXPLANATION NEEDED

Mathematics

1 answer:

dimaraw [331]3 years ago

3 0

Answer:

B is the correct answer (Check the explanation below)

Step-by-step explanation:

Probability of boys who do play = 1593/2451 = 0.6499 or 64.99% (if you times by 100 to change to percentage)

Probability of boys who do not play =858/2451 = 0.35 or 35%

Probability of girls who do play = 1361/2996 = 0.4542 or 45.42%

Probability of girls who do not play = 1635/2996 = 0.5457 or 54.57%

Probability of boys and girls who play = 2954/5447 = 0.5423 or 54.23%

Probability of boys and girls who do not play = 2493/5447 =0.4577 or 45.77%

you can see the correct statement is

Probability of girls who do play = 1361/2996 = 0.4542 or 45.42%

total number of girls is 2996 and we found out almost 54% do not play and almost 45% play

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Can someone please help me witch is the answer 20 points to the one who can answer first

ladessa [460]

First, let's find the slope.

Slope = (7 - (-3)) / (2 - 0) = (7 + 3) / 2 = 10 / 2 = 5

So far our equation looks like: y = 5x + b

Leta plug one of the points into our equation to find b.

-3 = 5(0) + b

Simplify.

-3 = b

The equation is: y = 5x - 3

Answer choice B is correct.

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3 years ago

Four friends are out for a walk at night and come to an old bridge. it isn’t safe to cross the bridge without a flashlight, and

Anna71 [15]

First the person with a flashlight and one of his friends cross the bridge. After that same person with a flashlight comes back and leads another friend to the other side. Finally he comes back again and leads the last of them.
Number of times that he will have to cross the bridge is 5 ( five ).

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3 years ago

Number 8 please! Please!

MariettaO [177]

Well we know she filled up her car 11 times each with 14 gallons.

All we have to do is multiply 11 by 14
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Now the question says to estimate. And our answer can be rounded down to 150 gallons.

So your answer is..
B.) 150 gallons.

Good Luck! :)

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3 years ago

Read 2 more answers

Stephanie has 6 classes a day at school. Each class is 52 minutes long. She goes to school 5 days a week. How many minutes does

Yakvenalex [24]

Answer:

1560 minutes

Step-by-step explanation:

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so that means, she spends 1560 minutes in class

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3 years ago

Read 2 more answers

Power +, Inc. produces AA batteries used in remote-controlled toy cars. The mean life of these batteries follows the normal prob

Novay_Z [31]

Answer:

a) By the Central Limit Theorem, it is approximately normal.

b) The standard error of the distribution of the sample mean is 1.8333.

c) 0.1379 = 13.79% of the samples will have a mean useful life of more than 38 hours.

d) 0.7939 = 79.39% of the samples will have a mean useful life greater than 34.5 hours

e) 0.656 = 65.6% of the samples will have a mean useful life between 34.5 and 38 hours

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the z-score of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

Mean of 36 hours and a standard deviation of 5.5 hours.

This means that $\mu = 36, \sigma = 5.5$

a. What can you say about the shape of the distribution of the sample mean?

By the Central Limit Theorem, it is approximately normal.

b. What is the standard error of the distribution of the sample mean? (Round your answer to 4 decimal places.)

Sample of 9 means that $n = 9$ . So

$s = \frac{\sigma}{\sqrt{n}} = \frac{5.5}{\sqrt{9}} = 1.8333$

The standard error of the distribution of the sample mean is 1.8333.

c. What proportion of the samples will have a mean useful life of more than 38 hours?

This is 1 subtracted by the pvalue of Z when X = 38. So

$Z = \frac{X - \mu}{\sigma}$

By the Central Limit Theorem

$Z = \frac{X - \mu}{s}$

$Z = \frac{38 - 36}{1.8333}$

$Z = 1.09$

$Z = 1.09$ has a pvalue of 0.8621

1 - 0.8621 = 0.1379

0.1379 = 13.79% of the samples will have a mean useful life of more than 38 hours.

d. What proportion of the sample will have a mean useful life greater than 34.5 hours?

This is 1 subtracted by the pvalue of Z when X = 34.5. So

$Z = \frac{X - \mu}{s}$

$Z = \frac{34.5 - 36}{1.8333}$

$Z = -0.82$

$Z = -0.82$ has a pvalue of 0.2061.

1 - 0.2061 = 0.7939

0.7939 = 79.39% of the samples will have a mean useful life greater than 34.5 hours.

e. What proportion of the sample will have a mean useful life between 34.5 and 38 hours?

pvalue of Z when X = 38 subtracted by the pvalue of Z when X = 34.5. So

0.8621 - 0.2061 = 0.656

0.656 = 65.6% of the samples will have a mean useful life between 34.5 and 38 hours

4 0

3 years ago