Solve the inequality. 6x + 6

Annual starting salaries in a certain region of the U. S. for college graduates with an engineering major are normally distribut

defon

Answer:

0.8665 = 86.65% probability that the sample mean would be at least $39000

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 $39725 and standard deviation $7320.

This means that $\mu = 39725, \sigma = 7320$

Sample of 125:

This means that $n = 125, s = \frac{7320}{\sqrt{125}} = 654.72$

The probability that the sample mean would be at least $39000 is about?

This is 1 subtracted by the pvalue of Z when X = 39000. So

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

By the Central Limit Theorem

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

$Z = \frac{39000 - 39725}{654.72}$

$Z = -1.11$

$Z = -1.11$ has a pvalue of 0.1335

1 - 0.1335 = 0.8665

0.8665 = 86.65% probability that the sample mean would be at least $39000

4 0

3 years ago

Select all of the proportional relationships

LenKa [72]

A,D can I get my Brainly

7 0

3 years ago

Read 2 more answers

What are the domain and range of the function f(x)= square rootx-7+9?

FinnZ [79.3K]

Answer:

Domain: [7, ∞)

Range: [9, ∞)

Step-by-step explanation:

1) This question may be easily answered if you are aware of the shape of the graph of sq. root x, and the effect of translations to graphs.

1. x - 7 means that the original graph is translated 7 units in the positive direction of the x-axis (ie. to the right), thus the minimum value for x is also shifted from 0 to 7

2. the + 9 means that the graph is translated 9 units in the positive direction of the y-axis (ie. up), thus the minimum y-value is also shifted from 0 to 9

3. We know that the graph will continue to infinity, both in the x- and y-direction

Thus, the domain would be [7, ∞) and the range [9, ∞)

2) Another way to think about it is to ask yourself when it would make sense for the graph to exist. For this, we must consider that you cannot take the square root of a negative number.

Thus, if we have the square root of (x - 7), for what value of x would (x - 7) be negative? If x = 7:

x - 7 = 7 - 7 = 0

Therefor, any x-value less than 7 will lead to a negative answer, which wouldn't be practical. Any value equal to or greater than 7 will lead to a positive answer, thus the permissible values for x are from 7 to infinity, and so the domain is [7, ∞) (note that square brackets are used for 7 as it is included in the domain, whereas infinity is always closed with round brackets).

If we have already found the domain, then we can simply substitute the values for this into the equation to obtain the range (note that this will work for a square root function, however some functions will have turning points and in this case you must calculate the range based on the turning points as well as the minimum and maximum x-values):

if x = 7: y = sq. root (7-7) + 9

= 9

This is the minimum value for y

if we have x = ∞, then the y value will also be infinitely great, therefor the maximum y-value is also ∞. Thus, the range is [9, ∞).

These questions are much easier to solve however if you are already aware of the basic graph and the effect of dilations, translations and reflections so that you may visualise it better.

4 0

3 years ago

Find two consecutive even integers

Fantom [35]

You can set up a system of equations with x being the smaller number and y being the larger number. So the first equation would be 2y=5x-14 and the second equation would be x=y-2. You can solve by substitution and substitute y-2 into the x in the first equation to get 2y=5(y-2)-14. You can solve this out and it ends up simplifying to y=8. So you know the larger number is 8. So since the larger number is 8 and they are consecutive even integers, the smaller number must be 6. So the two numbers would be 6 and 8.

8 0

3 years ago

Don’t really understand it someone help

stich3 [128]

Answer:

n = 8 or n = −2 is the correction solution.

Step-by-step explanation:

As the absolute value equation is given:

| n−3 | = 5

We know either n − 3 = 5 or n − 3 = −5

n − 3 = 5 (First Possibility)

n − 3 + 3 = 5 + 3

n = 8

n − 3 = -5 (Second Possibility)

n = -5 + 3

n = -2

So, n = 8 or n = −2 is the correction solution.

Keywords: absolute value equation

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7 0

3 years ago

Solve the inequality. 6x + 6 < 4x − 3