Hello please help me quick!

The probability that your call to a service line is answered in less than 30 seconds is 0.85. Assume that your calls are indepen

aev [14]

Answer:

a) 0.1720

b) 0.8298

c) 19

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:

$p = 0.85$

(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

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

$P(X = 9) = C_{12,9}.(0.85)^{9}.(0.15)^{3} = 0.1720$

(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

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

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

$P(X = 16) = C_{20,16}.(0.85)^{16}.(0.15)^{4} = 0.1821$

$P(X = 17) = C_{20,17}.(0.85)^{17}.(0.15)^{3} = 0.2428$

$P(X = 18) = C_{20,18}.(0.85)^{18}.(0.15)^{2} = 0.2293$

$P(X = 19) = C_{20,19}.(0.85)^{19}.(0.15)^{1} = 0.1368$

$P(X = 20) = C_{20,20}.(0.85)^{20}.(0.15)^{0} = 0.0388$

So

$P(X \geq 16) = P(X = 16) + P(X = 17) + P(X = 18) + P(X = 19) + P(X = 20) = 0.1821 + 0.2428 + 0.2293 + 0.1368 + 0.0388 = 0.8298$

(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

$E(X) = 22*0.85 = 18.7$

The nearest integer to 18.7 is 19.

7 0

3 years ago

What are the coordinates of the point?

kenny6666 [7]

D -2, 4 is in the second quadrant because the -x brings it to the left side and the positive 4 puts it in the upper of the left side which is the second quadrant

7 0

3 years ago

How do i do this (10 points) PLZ HELP

OleMash [197]

Bro that is easy just pau

8 0

2 years ago

Read 2 more answers

Reflect quadrilateral CJKM across the y-axis. Find the location of K'.

Montano1993 [528]

$K(1,4)\rightarrow K^{\prime}(-1,4)$

Explanation

Step 1

find the coordinate of every point of the quadrilateral

C(-3,1)

J(0,1)

K(1,4)

M(4,-2)

Step 2

When you reflect a point across the y-axis, the y-coordinate remains the same, but the x-coordinate is transformed into its opposite (its sign is changed).

so

$(x,y)\rightarrow reflect\text{ across y -Ax is}\rightarrow(-x,y)$

therefore

$\begin{gathered} C\mleft(-3,1\mright)\rightarrow C^{\prime}(3,1) \\ J\mleft(0,1\mright)\rightarrow J^{\prime}(0,1) \\ K\mleft(1,4\mright)\rightarrow K^{\prime}(-1,4) \\ M(4,-2)\rightarrow M^{\prime}(-4,-2) \end{gathered}$

so, the answer is

$K^{\prime}(-1,4)$

i hope this helps you

4 0

1 year ago

3,5,8,12....... state the rule in the sequence

amm1812

2n + 1

the number before n is the difference (what it goes up in), and the second is the ‘zeroth’ term: you take away the 2 you got from the first value, 3, and get 1 :)

8 0

3 years ago