24a-22=-4(1-6a) solve for a

To decrease the impact on the environment, factory chimneys must be high enough to allow pollutants to dissipate over a larger a

Komok [63]

Answer:

The probability hat the sample mean height for the 40 chimneys is greater than 102 meters is 0.1469.

Step-by-step explanation:

Let the random variable X be defined as the height of chimneys in factories.

The mean height is, μ = 100 meters.

The standard deviation of heights is, σ = 12 meters.

It is provided that a random sample of n = 40 chimney heights is obtained.

According to the Central Limit Theorem if we have an unknown population with mean μ and standard deviation σ and appropriately huge random samples (n > 30) are selected from the population with replacement, then the distribution of the sample means will be approximately normally distributed.

Then, the mean of the distribution of sample means is given by,

$\mu_{\bar x}=\mu$

And the standard deviation of the distribution of sample means is given by,

$\sigma_{\bar x}=\frac{\sigma}{\sqrt{n}}$

Since the sample selected is quite large, i.e. n = 40 > 30, the central limit theorem can be used to approximate the sampling distribution of sample mean heights of chimneys.

$\bar X\sim N(\mu_{\bar x},\ \sigma^{2}_{\bar x})$

Compute the probability hat the sample mean height for the 40 chimneys is greater than 102 meters as follows:

$P(\bar X>102)=P(\frac{\bar X-\mu_{\bar x}}{\sigma_{\bar x}})>\frac{102-100}{12/\sqrt{40}})$

$=P(Z>1.05)\\=1-P(Z$

*Use a z-table fr the probability.

Thus, the probability hat the sample mean height for the 40 chimneys is greater than 102 meters is 0.1469.

8 0

3 years ago

You previously found the mean of this data set. Use that in answering the question. 63, 89, 92, 73, 79, 72, 34, 36, 94, 21, 25,

kicyunya [14]

Answer:

Sum of squares of differences = 11239.74

Step-by-step explanation:

We are given the following data set:

63, 89, 92, 73, 79, 72, 34, 36, 94, 21, 25, 93, 22, 90, 79

We have to calculate the sum of square of the data set.

Formula:

$\text{Sum of square of differences} = \sum (x_i -\bar{x})^2$

where $x_i$ are data points, $\bar{x}$ is the mean and n is the number of observations.

$Mean = \displaystyle\frac{\text{Sum of all observations}}{\text{Total number of observation}}$

$Mean =\displaystyle\frac{962}{15} = 64.13$

Sum of squares of differences =

1.284444444 + 618.3511113 + 776.5511113 + 78.61777778 + 221.0177779 + 61.88444445 + 908.0177776 + 791.4844443 + 892.017778 + 1860.484444 + 1531.417778 + 833.2844446 + 1775.217777 + 669.0844446 + 221.0177779

= 11239.74

3 0

3 years ago

If (x + 8) is a factor of f(x), which of the following must be true?

Sedaia [141]

Answer:

f(-8) = 0

Step-by-step explanation:

If (x+8) is a factor of f(x), then for some expression p, we have ...

f(x) = (x+8)p

Evaluated at x=-8, this gives ...

f(-8) = (-8+8)p = 0p

f(-8) = 0 . . . . must be true

_____

Similarly, f(8) = (8+8)p = 16p. This may or may not be zero, depending on the factors of p. The only offered statement that must be true is the one shown above.

6 0

3 years ago

Read 2 more answers

Use substitution to write an equivalent quadiatic equation ( 3x^2)^2+7(3x +2) -8=0

mezya [45]

Answer:

9x^4+21x+6=0

Step-by-step explanation:

( 3x^2)^2+7(3x +2) -8=0

((3^2)*(x^2)^2)+(7*3x)+(7*2)-8=0

9(x^4)+21x+14-8=0

9x^4+21x+6=0

7 0

3 years ago

Simplify. Use a horizontal format. (-2y2 - 4y - 11) + (4y2 - 4y)

dimulka [17.4K]

-4y-11 that the answer hope it helps

6 0

3 years ago