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4 years ago

Find all real numbers s such that -2(s - 7) > 4s + 8. Give your answer as an interval.

Mathematics

2 answers:

Sedaia [141]4 years ago

8 0

-2s + 14 > 4s + 8
6 > 6s
s < 1
So it's {-<span>∞, . . . . ., -2, -1, 0}

Hope this helps.</span>

Tems11 [23]4 years ago

7 0

The process above is correct. Another way to write the answer is (negative infinity,1)

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BRAINLIEST! HELP ASAP MATH PLSSS

bearhunter [10]

Answer: The answer would be the second one.

Step-by-step explanation:

It is hard to explain but, I made and equation that would go with the problem which would be 2 points for every goal plus the free goals for every goal. (2g+f) and in then end it should all equal 15 so the equation so far would be 2g+f =15. This then leave you with three answers left. then I had plugged in a random number to solve it. g and f exacly should be the same number because for every goal you get a free point so if you get one goal then one extra point, if three goals then three extra points. so if you plug in 5 then 2 times 5 plus 5 is 15. The similarities between g and f is if you subtract them it is always going to be zero. Which makes the second answer correct for this problem.

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3 years ago

Explain how to solve 7 + x > 12 .Tell what property of inequality you would use

Maurinko [17]

Answer:

x > 5

Step-by-step explanation:

isolate x by subtracting 7 from both sides

x > 12 - 7

x > 5

3 0

4 years ago

A statistician calculates that 8% of Americans own a Rolls Royce. If the statistician is right, what is the probability that the

hichkok12 [17]

Answer:

0.007 = 0.7% probability that the proportion of Rolls Royce owners in a sample of 595 Americans would differ from the population proportion by more than 3%

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 establishes 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.

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean $\mu = p$ and standard deviation $s = \sqrt{\frac{p(1-p)}{n}}$

A statistician calculates that 8% of Americans own a Rolls Royce.

This means that $p = 0.08$

Sample of 595:

This means that $n = 595$

Mean and standard deviation:

$\mu = p = 0.08$

$s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\frac{0.08*0.92}{595}} = 0.0111$

What is the probability that the proportion of Rolls Royce owners in a sample of 595 Americans would differ from the population proportion by more than 3%?

Proportion above 8% + 3% = 11% or below 8% - 3% = 5%. Since the normal distribution is symmetric, these probabilities are equal, and so we find one of them and multiply by 2.

Probability the proportion is less than 5%:

P-value of Z when X = 0.05. So

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

By the Central Limit Theorem

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

$Z = \frac{0.05 - 0.08}{0.0111}$

$Z = -2.7$

$Z = -2.7$ has a p-value of 0.0035

2*0.0035 = 0.0070

0.007 = 0.7% probability that the proportion of Rolls Royce owners in a sample of 595 Americans would differ from the population proportion by more than 3%

8 0

3 years ago

The amount of time that a customer spends waiting at an airport check-in counter is a random variable with mean 8.2 minutes and

Ksju [112]

Answer:

A) 1

B) 1

C) 0

Step-by-step explanation:

The amount of time that a customer spends waiting at an airport check-in counter is a random variable with mean 8.2 minutes and standard deviation 1.5 minutes. Suppose that a random sample of n = 49 customers is observed. Find the probability that the average time waiting in line for these customers is A) Less than 10 minutes B) Between 5 and 10 minutes C) Less than 6 minutes

We solve this question using the z score formula

z = (x-μ)/σ/√n, where

x is the raw score

μ is the population mean

σ is the population standard deviation.

n = number of random samples

A) Less than 10 minutes

x < 10

z = 10 - 8.2/ 1.5 / √49

z = 8.4

P-value from Z-Table:

P(x<10) = 1

B) Between 5 and 10 minutes

For x = 5 minutes

z = 5 - 8.2/ 1.5 / √49

z = -14.93333

P-value from Z-Table:

P(x = 5) = 0

For x = 10 minutes

z = 10 - 8.2/ 1.5 / √49

z = 8.4

P-value from Z-Table:

P(x = 10) = 1

The probability that the average time waiting in line for these customers is between 5 and 10 minutes

P(x = 10) - P(x = 5)

= 1 - 0

= 1

C) Less than 6 minutes

x < 6

z = 6 - 8.2/ 1.5 / √49

z = -10.26667

P-value from Z-Table:

P(x<6) = 0

6 0

3 years ago

Use the equation 15% = 10% + 5% to find a 15% tip on a bill of $14.85. (Round the bill to the nearest dollar before finding the

Ymorist [56]

The tip amount is $2.23

Because...

14.85 x .15 = 2.2275

Rounding gets you your answer . Good luck (:

3 0

3 years ago