Please help me solve.

A circular sector has a central angle of π6 radians and a radius of 9 ft.

ohaa [14]

Answer:

$\approx \: 21.2 \: {ft}^{2}$

Step-by-step explanation:

$central \: \angle = \frac{\pi ^{c} }{6} = 30 \degree \\ \\ area \: of \: the \: sector = \frac{30 \degree}{360 \degree} \times \pi {(9)}^{2} \\ \\ = \frac{1}{12} \times 3.14 \times 81 \\ \\ = \frac{1}{12} \times 254.34 \\ \\ = 21.195 \: {ft}^{2} \\ \\ \approx \: 21.2 \: {ft}^{2}$

8 0

2 years ago

Read 2 more answers

The probability that your call to a service line is answered in less than 30 seconds is 0.75. Assume that your calls are indepen

vfiekz [6]

Answer:

a) 0.2581

b) 0.4148

c) 17

Step-by-step explanation:

For each call, there are only two possible outcomes. Either they are answered in less than 30 seconds. Or they are not. The probabilities for each call are independent. So we use the binomial probability distribution to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

In this problem we have that:

$p = 0.75$

a. If you call 12 times, what is the probability that exactly 9 of your calls are answered within 30 seconds? Round your answer to four decimal places (e.g. 98.7654).

This is $P(X = 9)$ when $n = 12$ . So

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 9) = C_{12,9}.(0.75)^{9}.(0.25)^{3} = 0.2581$

b. If you call 20 times, what is the probability that at least 16 calls are answered in less than 30 seconds? Round your answer to four decimal places (e.g. 98.7654).

This is $P(X \geq 16)$ when $n = 20$

So

$P(X \geq 16) = P(X = 16) + P(X = 17) + P(X = 18) + P(X = 19) + P(X = 20)$

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 16) = C_{20,16}.(0.75)^{16}.(0.25)^{4} = 0.1897$

$P(X = 17) = C_{20,17}.(0.75)^{17}.(0.25)^{3} = 0.1339$

$P(X = 18) = C_{20,18}.(0.75)^{18}.(0.25)^{2} = 0.0669$

$P(X = 19) = C_{20,19}.(0.75)^{19}.(0.25)^{1} = 0.0211$

$P(X = 20) = C_{20,20}.(0.75)^{20}.(0.25)^{0} = 0.0032$

So

$P(X \geq 16) = P(X = 16) + P(X = 17) + P(X = 18) + P(X = 19) + P(X = 20) = 0.1897 + 0.1339 + 0.0669 + 0.0211 + 0.0032 = 0.4148$

c. If you call 22 times, what is the mean number of calls that are answered in less than 30 seconds? Round your answer to the nearest integer.

The expected value of the binomial distribution is:

$E(X) = np$

In this question, we have $n = 22$

So

$E(X) = 22*0.75 = 16.5$

The closest integer to 16.5 is 17.

7 0

2 years ago

What’s the radius, circumference, and area?

Ivenika [448]

Answer:

Radius: 19 yards

Diameter: 38 yards

Circumference: 119. 32

Step-by-step explanation:

Radius

To find the radius you divide the diameter by 2 because, the diameter is a; a straight line passing from side to side through the center of a body or figure, especially a circle or sphere.

So 38 ÷ 2 = 19

So the radius is 19.

_____________________

Circumference

To find the Circumference you need to do 2·π·19

C=2·π

2·π = 6.28

6.28 · 19 = 119. 32

Circumference is 119. 32

8 0

2 years ago

Mrs cunningham wants to use rubber tiles to cover the floor of an indoor playground

snow_lady [41]

Answer:

the unit cost per rubber tile is $$$$$$$$$$$$$6

Step-by-step explanation:

..

4 0

2 years ago

Select the correct answer.

ValentinkaMS [17]

Answer:

A

Step-by-step explanation:

The equation of a line in slope- intercept form is

y = mx + c ( m is the slope and c the y- intercept )

Here m = - 3 , thus

y = - 3x + c ← is the partial equation

To find c substitute (7, 8) into the partial equation

8 = - 21 + c ⇒ c = 8 + 21 = 29

y = - 3x + 29 → A

4 0

3 years ago