Edwin says that when (x + 2)2 = 49, that x + 2 = 7.

You are planning to make a collage and are gathering materials.for the backing you will use a piece of heavy recycled cardboard

Lunna [17]

1. 4 3/4 feet = 19/4 feet
2 2/5 feet=12/5 feet.
multiplying them together yields
$\frac{19}{4} * \frac{12}{5} =$
$= \frac{57}{5} = 11.4 ft^{2}$

Part 2:
11.4 ft^2 - 4 1/2 ft^2=
11.4-4.5=6.9 ft^2 = 69/10 ft^2 left after you subtract the decoration in the middle
Now you're trying to find now many rectangular cutouts (that each are 3/8 ft^2) will fit in the remaining space.
You do that by dividing the remaining space left by 3/8:
$\frac{69}{10} / \frac{3}{8} = \frac{69}{10} * \frac{8}{3} = \frac{92}{5}$
since you have to have a whole number of cutouts, you round 92/5 down to 90/5, which is 18 cutouts

5 0

3 years ago

What is the geometric mean of 8 and 2?

Molodets [167]

9514 1404 393

Answer:

4

Step-by-step explanation:

The geometric mean of two numbers is the square root of their product.

√(8·2) = √16 = 4

The geometric mean of 8 and 2 is 4.

__

The geometric mean of n numbers is the n-th root of their product.

6 0

3 years ago

A population has a mean of 200 and a standard deviation of 50. Suppose a sample of size 100 is selected and x is used to estimat

zmey [24]

Answer:

a) 0.6426 = 64.26% probability that the sample mean will be within +/- 5 of the population mean.

b) 0.9544 = 95.44% probability that the sample mean will be within +/- 10 of the population mean.

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal probability distribution

When the distribution is normal, we use the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore 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 pvalue, 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.

In this question, we have that:

$\mu = 200, \sigma = 50, n = 100, s = \frac{50}{\sqrt{100}} = 5$

a. What is the probability that the sample mean will be within +/- 5 of the population mean (to 4 decimals)?

This is the pvalue of Z when X = 200 + 5 = 205 subtracted by the pvalue of Z when X = 200 - 5 = 195.

Due to the Central Limit Theorem, Z is:

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

X = 205

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

$Z = \frac{205 - 200}{5}$

$Z = 1$

$Z = 1$ has a pvalue of 0.8413.

X = 195

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

$Z = \frac{195 - 200}{5}$

$Z = -1$

$Z = -1$ has a pvalue of 0.1587.

0.8413 - 0.1587 = 0.6426

0.6426 = 64.26% probability that the sample mean will be within +/- 5 of the population mean.

b. What is the probability that the sample mean will be within +/- 10 of the population mean (to 4 decimals)?

This is the pvalue of Z when X = 210 subtracted by the pvalue of Z when X = 190.

X = 210

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

$Z = \frac{210 - 200}{5}$

$Z = 2$

$Z = 2$ has a pvalue of 0.9772.

X = 195

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

$Z = \frac{190 - 200}{5}$

$Z = -2$

$Z = -2$ has a pvalue of 0.0228.

0.9772 - 0.0228 = 0.9544

0.9544 = 95.44% probability that the sample mean will be within +/- 10 of the population mean.

7 0

3 years ago

HELP MATH WHIZZES!! TON OF FREE POINTS, EASY GEOMETRY QUESTION FOR THE RIGHT ANSWER! WHO WILL WIN THIS?! NEED HELP, NOT WRONG AN

Radda [10]

The area of the trapezoid is the product of the height and the average of the two bases:
30 (25 + 33)/2 = 30 (58)/2 = 30 (29) = 870 square yd. 

But we want to exclude the area of the fountain. 
Since it's circular its area is π times the square of its radius, or 16π square yd. 

So the area of the park, excluding the fountain, is 
870 - 16π square yd, 
or about 820 square yd.

5 0

4 years ago

Read 2 more answers

2 138° 1 What is m 22?

yulyashka [42]

Answer:

Measure of angle 2 is 42.

If you are satisfied with the results then plz make me genius.

3 0

3 years ago