How do write 85 less than the product of 23 and an unknown number is 191.

A coffee pot holds 5 1/2 quartz of coffee. How much is his in cups?

pav-90 [236]

12 1/2 cups is equavelent

6 0

2 years ago

Refer to Exercise 3.122. If it takes approximately ten minutes to serve each customer, find the mean and variance of the total s

garri49 [273]

Answer

a. The expected total service time for customers = 70 minutes

b. The variance for the total service time = 700 minutes

c. It is not likely that the total service time will exceed 2.5 hours

Step-by-step explanation:

This question is incomplete. I will give the complete version below and proceed with my solution.

Refer to Exercise 3.122. If it takes approximately ten minutes to serve each customer, find the mean and variance of the total service time for customers arriving during a 1-hour period. (Assume that a sufficient number of servers are available so that no customer must wait for service.) Is it likely that the total service time will exceed 2.5 hours?

Reference

Customers arrive at a checkout counter in a department store according to a Poisson distribution at an average of seven per hour.

From the information supplied, we denote that

$X=$ Customers that arrive within the hour

and since $X$ follows a Poisson distribution with mean $\alpha$ = 7

Therefore,

$E(X)= 7$

$& V(X)=7$

Let $Y =$ the total service time for customers arriving during the 1 hour period.

Now, since it takes approximately ten minutes to serve each customer,

$Y=10X$

For a random variable $X$ and a constant $c$ ,

$E(cX)=cE(X)\\V(cX)=c^2V(X)$

Thus,

$E(Y)=E(10X)=10E(X)=10*7=70\\V(Y)=V(10X)=100V(X)=100*7=700$

Therefore the expected total service time for customers = 70 minutes

and the variance for serving time = 700 minutes

Also, the probability of the distribution $Y$ is,

$p_Y(y)=p_x(\frac{y}{10} )\frac{dx}{dy} =\frac{\alpha^{\frac{y}{10} } }{(\frac{y}{10})! }e^{-\alpha } \frac{1}{10}\\ =\frac{7^{\frac{y}{10} } }{(\frac{y}{10})! }e^{-7 } \frac{1}{10}$

So the probability that the total service time exceeds 2.5 hrs or 150 minutes is,

$P(Y>150)=\sum^{\infty}_{k=150} {p_Y} (k) =\sum^{\infty}_{k=150} \frac{7^{\frac{k}{10} }}{(\frac{k}{10})! }.e^{-7} .\frac{1}{10} \\=\frac{7^{\frac{150}{10} }}{(\frac{150}{10})! } .e^{-7}.\frac{1}{10} =0.002$

0.002 is small enough, and the function $\frac{7^{\frac{k}{10} }}{(\frac{k}{10} )!} .e^{-7}.\frac{1}{10}$ gets even smaller when $k$ increases. Hence the probability that the total service time exceeds 2.5 hours is not likely to happen.

3 0

3 years ago

IF 24% of the sixth grade class is in Mrs Whites class and Mrs White has 30 students how many sixth graders are there in all?

Alexeev081 [22]

Given

0.24 × (number of 6th grade students) = 30

Find

(number of 6th grade students

Solution

Divide by 0.24.

... (number of 6th grade students) = 30/0.24 = 125

4 0

3 years ago

Read 2 more answers

4688-3) -30X-5 CX-5)

pshichka [43]

Answer:

x = 13/3

Step-by-step explanation:

4(8x-3) - 30x = 5(x-5)

Distribute

32x - 12 - 30x = 5x -25

Combine like terms

2x -12 = 5x-25

Subtract 2x from each side

2x-12-2x = 5x-2x -25

-12 = 3x-25

Add 25 to each side

-12+25 = 3x-25+25

13 = 3x

Divide each side by 3

13/3 = x

4 0

3 years ago

Read 2 more answers

How to convert 11/27 into a decimal

il63 [147K]

Answer:

11 ÷ 27 = 0.407407

Step-by-step explanation:

Una fracción, como 11/27, tiene un numerador y un denominador separado por una línea divisoria.

11 es el numerador, porque es el número de arriba de la línea divisoria.

27 es el denominador porque es el número de abajo de la línea divisoria.

Para convertir 11/27 a decimal, divide el numerador por el denominador.

4 0

3 years ago