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3 years ago

A sphere has a volume of 850 m^3 find its surface area

Mathematics

1 answer:

VashaNatasha [74]3 years ago

7 0

Answer:

SA ≈ 434.5 cm²

Step-by-step explanation:

The volume (V) of a sphere is calculated as

V = $\frac{4}{3}$ πr³ ( r is the radius )

The surface area (SA) is calculated as

SA = 4πr²

To find r use the volume formula

$\frac{4}{3}$ πr³ = 850 ( multiply both sides by $\frac{3}{4}$ to clear the fraction )

πr³ = 637.5 ( divide both sides by π )

r³ = $\frac{637.5}{\pi }$ ( take the cube root of both sides )

r = $\sqrt[3]{\frac{637.5}{\pi } }$ ≈ 5.88 cm ( to 2 dec. places )

Then

SA = 4π × 5.88² ≈ 434.5 cm² ( to 1 dec. place )

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Answer:

The sum of interior angles of a nonagon is 1260° with 140° for each angle in a regular nonagon

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3 years ago

Please Help! i need explanations too. Thank you

Lady bird [3.3K]

Answer:

Step-by-step explanation:

The most important thing to remember when solving equations is whatever you do to one side, you must do to the other.

1. (15m + 3)/2 = -6

First, we can simplify by removing the fraction:

15m + 3 = -6 x 2 (multiply both sides by 2)

15m + 3 = -12

15m = -12 - 3 (subtract by 3 on both sides)

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first, we'll add both sides by 15

2/3x = -12 + 15

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x = 3/(2/3) both sides divided by 2/3, just put that in your calculator, if you can't do it in your head

x = 4 1/2

3. -7x + 3 = -15/2

We can remove the fraction by doing the same thing as in the first question.

2(-7x + 3) = -15

-14x + 6 = -15

14x = -15 -6

14x = -21

x = -21/14

x = -1 1/2

4. 4x + 1/2(12x + 2) = 3

First we need to simplify by expanding:

4x + 6x + 1 = 3

Now we collect the like terms to further simplify the equation

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10x = 2

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x = 1/5

5. 3/2(x + 8) = 6x

We're going to start by removing the brackets, this time by multiplying the fraction on both sides:

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Now the questions, some of them are personal, so I won't be able to answer them for you, but I can try with the others:

These types of problems are fractional equations, and you need to find the value of the variable, which in this case was x.

I'm not sure what information you already know, so you'll have to think on that one.

Strategies you could use or try include multiplying, dividing, subtracting and adding on both sides as well as collecting like terms and expanding.

Hope this helped,

Cate

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3 years ago

You went to the store for snacks. You purchased 2 bags of chips for $0.75 each, a bottle of juice for $1.09, a donut for $0.68,

Anuta_ua [19.1K]

Answer:

So add all the numbers together 0.75 + 0.75 = $1.50

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You have $4.14 that you spent. The cashier should give you back $5.86.

So yes, you gave the cashier enough money and you got back money too.

Please mark me brainless.

7 0

4 years ago

The weights of a certain dog breed are approximately normally distributed with a mean of 49 pounds, and a standard deviation of

AlekseyPX

Answer:

a. 74.86%

b. 50%

c. 50%

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.

Normally distributed with a mean of 49 pounds, and a standard deviation of 6 pounds.

This means that $\mu = 49, \sigma = 6$

a. Find the percentage of dogs of this breed that weigh less than 53 pounds.

The proportion is the p-value of Z when X = 53. So

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

$Z = \frac{53 - 49}{6}$

$Z = 0.67$

$Z = 0.67$ has a p-value of 0.7486.

0.7486*100% = 74.86%, which is percentage of dogs of this breed that weigh less than 53 pounds.

b. Find the percentage of dogs of this breed that weigh less than 49 pounds.

p-value of Z when X = 49, so:

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

$Z = \frac{49 - 49}{6}$

$Z = 0$

$Z = 0$ has a p-value of 0.5

0.5 = 50% of dogs of this breed that weigh less than 49 pounds.

c. Find the percentage of dogs of this breed that weigh more than 49 pounds.

1 subtracted by the p-value of Z when X = 49, so:

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

$Z = \frac{49 - 49}{6}$

$Z = 0$

$Z = 0$ has a p-value of 0.5.

1 - 0.5 = 0.5 = 50% of dogs of this breed that weigh more than 49 pounds.

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3 years ago

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jarptica [38.1K]

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3 years ago