What are the coordinate pairs of AB?

What is (x - 4y) (-3x - 2y) = ?

Artemon [7]

The answer is -3x^2+10xy+8y^2

3 0

3 years ago

What are some uses for the distance formula?

lbvjy [14]

To find the area of a building.
and to make a small farm

8 0

3 years ago

What property is 4x + 8 = 28

Verdich [7]

Answer:

x=5

Step-by-step explanation:

4x + 8 = 28,

it's rather straight forward,

you would subtract 8 from the left side,

doing the same on the right.

now you have

4x = 20

x= 20/4

x=5

hope this helps.

4 0

3 years ago

the ratio of girls to boys in mrs tuners class is 3:4. there 9 girls in mrs tuners class. how many boys are in mrs tuners class

Aleonysh [2.5K]

Answer:

12

Step-by-step explanation:

You set up cross multiplication 3/4 x 9/x, you go 4x9=36 divided by 3 equals 12

7 0

2 years ago

Life Expectancies In a study of the life expectancy of people in a certain geographic region, the mean age at death was years an

Sphinxa [80]

Answer:

The probability that the mean life expectancy of the sample is less than X years is the p-value of $Z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}$ , in which $\mu$ is the mean life expectancy, $\sigma$ is the standard deviation and n is the size of the sample.

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.

We have:

Mean $\mu$ , standard deviation $\sigma$ .

Sample of size n:

This means that the z-score is now, by the Central Limit Theorem:

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

Find the probability that the mean life expectancy will be less than years.

The probability that the mean life expectancy of the sample is less than X years is the p-value of $Z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}$ , in which $\mu$ is the mean life expectancy, $\sigma$ is the standard deviation and n is the size of the sample.

8 0

2 years ago