Please help me with mathh !!!

The sum of 2 integers is 9. the product of the integers is 14 what are the integers

chubhunter [2.5K]

Answer:

7 and 2

Step-by-step explanation:

7 plus 2 is 9. 7 times 2 is 14.

3 0

3 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

3 years ago

A woman plans to use one fourth of a 48 foot x 100 foot rectangular backyard to plant garden. Find the perimeter of the garden i

nataly862011 [7]

Answer: 160ft.

Step-by-step explanation:

First find the area of the 48ft x 100ft rectangular back yard.

Area of a rectangular = L x B

= 48 x 100

= 4800ft²

Now, find 1/4 of the rectangular backyard meant for garden

= 1/4 of 4800

= 1200ft²

Step 2:

To find the perimeter of the garden,first find the length and breath of the garden. From the dimension of the garden, the length is 40ft > width. In interpreting this,

We make the width of the garden to be. B = xft,

Therefore. L = (x + 40)ft

Now equate the product of this to 1200ft

x(x + 40) = 1200

Open the bracket

x² + 40x = 1200

x² + 40x - 1200 = 0

This is now a quadratic expression. Solving for x using any methods

x² + 60x - 20x - 1200 = 0

Solving by grouping

x(x + 60) - 20(x + 60) = 0

Collect common factors here

(x + 60)(x - 20) = 0

Therefore, x = -60 or 20

Remember, x cannot be negative, so x = 20ft. The width = 20ft, and the length = 60ft.

With this, we can determine the perimeter.

Formula for perimeter of a rectangular block

= 2( L + B )

= 2( 60 + 20 )

= 2(80)

= 2 x 80

= 160ft.

8 0

3 years ago

Can u guys help me with #1 plz guys now

myrzilka [38]

3

the area is 41.6cm which is 1foot 4 3/8 inches.

So 6in + 6in + 6in = 1ft 6in, which will be enough to cover the floor.

3 0

3 years ago

What is the initial value of the function represented by this table?

Julli [10]

Answer:

3

Step-by-step explanation:

Initial value represents the value of the function when the input (which here is x) is zero. Looking at the table, we see that if x = 0, y = f(0) = 3.

The initial value of this function is 3.

4 0

3 years ago

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