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3 years ago

Find the area of each circle. Round to the nearest tenth. Use 3.14 for π.

Mathematics

1 answer:

joja [24]3 years ago

3 0

Answer:

1. 490.6 mm²

2. 14.1 ft²

Step-by-step explanation:

1. 3.14×(12.5)²= 3.14 × 156.25 =490.6mm²

2. ½×3.14×3²= 3.14×4.5= 14.1 ft²

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How do you write <br> 3.7 × 104 in standard form

Sedbober [7]

the answer is

$37 \times {10}^{ - 1} \times 1.04 \times {10}^{2}$

4 0

3 years ago

8.52 The heights of 2-year-old children are normally distributed with a mean of 32 inches and a standard deviation of 1.5 inches

sweet [91]

Answer:

Heights of 29.5 and below could be a problem.

Step-by-step explanation:

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.

The heights of 2-year-old children are normally distributed with a mean of 32 inches and a standard deviation of 1.5 inches.

This means that $\mu = 32, \sigma = 1.5$

There may be a problem when a child is in the top or bottom 5% of heights. Determine the heights of 2-year-old children that could be a problem.

Heights at the 5th percentile and below. The 5th percentile is X when Z has a p-value of 0.05, so X when Z = -1.645. Thus

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

$-1.645 = \frac{X - 32}{1.5}$

$X - 32 = -1.645*1.5$

$X = 29.5$

Heights of 29.5 and below could be a problem.

4 0

2 years ago

6.3 x 10^14<br><img src="https://tex.z-dn.net/?f=6.3%20%5Ctimes%20%20%7B10%7D%5E%7B14%3F%7D%20" id="TexFormula1" title="6.3 \tim

Nutka1998 [239]

I'm assuming you're looking to find the expanded form of the number?

This number is in scientific notation. The easiest way to convert it to a normal number is to move the decimal place 14 to the right. I've attached a picture showing how to do this. You should get 630,000,000,000,000

There's a faster way to do this - notice that you need to move the decimal 14 to the right, and there's one number already after the decimal place. Therefore, 13 places will be filled with zeros. So, just write out 63 and add 13 zeros.

For more general help on scientific notation, check out these videos: https://www.khanacademy.org/math/pre-algebra/pre-algebra-exponents-radicals/pre-algebra-scientific-notation/v/scientific-notation-old

Hope that helps! Feel free to message me or leave a comment if I can clarify anything :)

7 0

3 years ago

jill mowed lawns for 3 hours and earned $7.20 per hour.Then she washed windows for 4 hours and earned $6.75 per hour. what were

Aleksandr-060686 [28]

Actually, she worked for seven hours, so I'll solve for that.

7.20 x 3 = 21.6

6.75 x 4 = 27

21.6 + 27 = 48.6

48.6 /2 = 24.3

Her average should be $24.3 If she did work six hours, just multiply 6.75 x 3 and do what I did.

5 0

3 years ago

Square A has a side length of (2x-7) and Square B has a side length of (-4x+18). How much bigger is the perimeter of Square B th

dusya [7]

4(2x-7)=8x-28
4(-4x+18)=-16x+72
(8x-28)-(-16x+73)

24x+45

8 0

3 years ago