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3 years ago

Find the area of the shaded reigon

Mathematics

1 answer:

nikdorinn [45]3 years ago

7 0

Answer:

40π/3 cm^2 ≈ 41.89 cm^2

Step-by-step explanation:

The centerline of the shaded region has a radius of 3cm+(4 cm)/2 = 5 cm. Its length is 1/3 that of the circumference of a circle with that radius (because 120° is 1/3 of 360°).

The area is the product of the centerline length and the width of the shaded area (4 cm).

shaded area = (1/3)(2π(5 cm))(4 cm)

shaded area = 40π/3 cm^2 ≈ 41.89 cm^2

<em>Alternate solution</em>

The area of the donut is the difference in the areas of the outer and inner circles:

πr₂² -πr₁² = π((7 cm)^2 -(3 cm)^2) = 40π cm^2

The are of the shaded region is (120°/360°) = 1/3 of that, so is

shaded area = (40/3)π cm^2

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If 40 men took 10 minutes to make 200 toys,how many man will take 40 minutes to make 350 toys?

Viktor [21]

40=4×10=200 toys
160=4×40=350 toys

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3 years ago

What is 6+r =5r-4(r+10)

White raven [17]

Answer:

no solution

Step-by-step explanation:

6+r=5r-4(r+10)

6+r=5r-4r-40

6+r=r-40

46+r=r

46=0r

no solution

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4 years ago

A fast-food restaurant has an automated beverage machine that dispenses a set amount of liquid based on a size setting. Suppose

SashulF [63]

Answer:

$n=(\frac{2.58(17)}{10})^2 =19.24 \approx 20$

So the answer for this case would be n=20 rounded up to the nearest integer would be the sample required to obatin a margin of erros or 10 ml at 99% of confidence

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

$\sigma =17$ represent the population standard deviation

n represent the sample size

Solution to the problem

The margin of error is given by this formula:

$ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (a)

And on this case we have that ME =10 and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=(\frac{z_{\alpha/2} \sigma}{ME})^2$ (b)

The critical value for 99% of confidence interval now can be founded using the normal distribution. And in excel we can use this formla to find it:"=-NORM.INV(0.005;0;1)", and we got $z_{\alpha/2}=2.58$ , replacing into formula (b) we got:

$n=(\frac{2.58(17)}{10})^2 =19.24 \approx 20$

So the answer for this case would be n=20 rounded up to the nearest integer would be the sample required to obatin a margin of erros or 10 ml at 99% of confidence

8 0

3 years ago

the local market is selling a pound of bananas for $0.55. if you bought 8 bananas for $1.44, what is the unit rate?

Black_prince [1.1K]

Answer:

$0.18

Step-by-step explanation:

Given that :

Number of bananas purchased = 8

Cost at which the 8 bananas were purchased = $1.44

The unit price of bananas can be obtained using the relation :

Total Cost of bananas / number of bananas

Unit price = $1.44 / 8

Unit price = $0.18

Price per unit of banana = $0.18

8 0

3 years ago

Find the equivalent expression to 9(2a+1)

Ivan

Answer:

18a + 9

Step-by-step explanation:

To find this, disperse the term 9 into the paranthesis by multiplying positive nine with both 2a and +1.

Then, form the new equation of 18a + 9.

Hope this helps!

3 0

4 years ago