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3 years ago

An arc length is a fractional part of the

Mathematics

1 answer:

LenaWriter [7]3 years ago

4 0

Answer:

Each of the 4 sectors have an area:

πR²/8 - πr²/8, where
R = 28/2 - 2 = 12 in
r = 6/2 = 3 in

Find the area:

A = π/8(12² - 3² ≈ 53 in²

Outer perimeter of the frame:

P = d + πd/2 =28( 1 + π/2) ≈ 72 in

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Simplify the expression below as much as possible.

Dima020 [189]

The answer is 8+1 which is D

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3 years ago

A room is 10ft tall, 25ft long, and 15ft wide. The cost of paint is $12/gal. Each gallon of paint covers 200sqft. What is the to

iVinArrow [24]

Answer:

800 sqft

Step-by-step explanation:

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3 years ago

A scale model of a rectangular building lot measures 7 feet by 5 feet. If the actual house will be built using a scale factor of

eimsori [14]

Answer:

The area of the actual building lot is $5,040\ ft^2$

Step-by-step explanation:

Scaling

The scaled rectangular building measures 7 feet by 5 feet. We know both magnitudes were scaled by a factor of 12, thus the real dimensions of the house to be built are 7*12=84 feet, and 5*12=60 feet.

The area of the actual building lot is calculated by:

$A=84\ ft*60\ ft=5,040\ ft^2$

The area of the actual building lot is $5,040\ ft^2$

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3 years ago

Mary wants to get a computer monitor for her desk which can hold a 22 inch monitor. She has found a monitor 16 inches wide and 1

Allushta [10]

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3 years ago

The mean number of words per minute (WPM) read by sixth graders is 84 with a standard deviation of 15 WPM. If 188 sixth graders

Anna007 [38]

Answer:

0.1836 = 18.36% probability that the sample mean would differ from the population mean by greater than 1.46 WPM

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.

The mean number of words per minute (WPM) read by sixth graders is 84 with a standard deviation of 15 WPM.

This means that $\mu = 84, \sigma = 15$

Sample of 188

This means that $n = 188, s = \frac{15}{\sqrt{188}}$

What is the probability that the sample mean would differ from the population mean by greater than 1.46 WPM?

Greater than 84 + 1.46 = 85.46 or less than 84 - 1.46 = 82.54. Since the normal distribution is symmetric, these probabilities are equal, so we find one of them and multiply by 2.

Probability is is less than 82.54.

P-value of Z when X = 82.54. So

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

By the Central Limit Theorem

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