All categories

3 years ago

The circumference of a circle is 9π m. What is the area of the circle? ASAP!

Mathematics

1 answer:

liubo4ka [24]3 years ago

4 0

Answer:

20.25 m²

Step-by-step explanation:

the area (A) and circumference (C) of a circle are calculated using the formulae

C = 2πr and A = πr² ( where r is the radius )

calculate the radius using the formula for circumference

2πr = 9π ( divide both sides by 2π )

r = $\frac{9\pi }{2\pi }$ = $\frac{9}{2}$ = 4.5, hence

A = π × 4.5² = 20.25π m²

You might be interested in

The diameter of the moon is 2,160 miles. A model has a scale of 1 in : 150 mi. What is the diameter of the model?

Charra [1.4K]

Answer:

The diameter of the model is 14.4 inches.

Step-by-step explanation:

The Diameter of the moon = 2,160 miles

The scale on the model represents 1 in = 150 miles

Let the model represents k inches in 2,160 miles.

So, by the Ratio of Proportionality:

$\frac{1}{150} = \frac{k}{2160}$

⇒ $k = \frac{2160}{150} \\\implies k = 14.4$

or, k = 14.4 inches

⇒On the scale 2160 miles is represented as 14.4 inches

Hence the diameter of the model is 14.4 inches.

3 0

3 years ago

Public opinion in the large city of Bedrock is that 60 percent of the residents are in favor of increasing taxes to fund alterna

uysha [10]

Answer: 0.8461

Step-by-step explanation:

Let p be the proportion of residents are against the increase of taxes to fund alternatives to drug addiction treatment.

As per given , we have p=0.40

A random sample is taken with size : n= 400

Expecting sample proportion : $\hat{p}=\dfrac{150}{400}=0.375$

Now , the probability that more than 150 of the residents surveyed will be against increasing taxes if a random sample of 400 residents are surveyed will be :

$P(p>0.375)=P(\dfrac{\hat{p}-p}{\sqrt{\dfrac{p(1-p)}{n}}}>\dfrac{0.375-0.40}{\sqrt{\dfrac{0.40(0.60)}{400}}})$

$=P(z>\dfrac{0.375-0.40}{\sqrt{\dfrac{0.40(0.60)}{400}}})\ \ [\because\ z=\dfrac{\hat{p}-p}{\sqrt{\dfrac{p(1-p)}{n}}}]$

$=P(z>-1.02)=P(z-z)=P(Z$

$\approx0.8461$ [By z-table]

Hence, the approximate probability that more than 150 of the residents surveyed will be against increasing taxes if a random sample of 400 residents are surveyed is 0.8461 .

4 0

4 years ago

Given the sequence in the table below, determine the sigma notation of the sum for term 4 through term 15. N an 1 4 2 −12 3 36 t

Rzqust [24]

By applying basic property of Geometric progression we can say that sum of 15 terms of a sequence whose first three terms are 5, -10 and 2 is $\sum_{n=4}^{15} 5(-2)^{n-1}$$$

<h3>What is sequence ?</h3>

Sequence is collection of numbers with some pattern .

Given sequence

$a_{1}=5\\\\a_{2}=-10\\\\\\a_{3}=20$

We can see that

$\frac{a_1}{a_2}=\frac{-10}{5}=-2\\$

and

$\frac{a_2}{a_3}=\frac{20}{-10}=-2\\$

Hence we can say that given sequence is Geometric progression whose first term is 5 and common ratio is -2

Now $n^{th}$ term of this Geometric progression can be written as

$T_{n}= 5\times(-2)^{n-1}$

So summation of 15 terms can be written as

$\sum_{n=4}^{15} T_{n}\\\\$\\$\sum_{n=4}^{15} 5(-2)^{n-1}$$$

By applying basic property of Geometric progression we can say that sum of 15 terms of a sequence whose first three terms are 5, -10 and 2 is $\sum_{n=4}^{15} 5(-2)^{n-1}$$$

To learn more about Geometric progression visit : brainly.com/question/14320920

8 0

3 years ago

1. i’ll give you brainliest if u get this right

Allisa [31]

Answer:

Step-by-step explanation:

34 and m=7

6 0

3 years ago

Evaluate the expression when b=4/5 and c=-3/8<br><br> 2c-b

timurjin [86]

Answer:

-1/20

Step-by-step explanation:

2(3/8) - 4/5

6/8 - 4/5

30/40 - 32/40

-2/40

-1/20

6 0

3 years ago