A statistics professor finds that when she schedules an office hour for student help, an average of 3.3 students arrive. Find the probability that in a randomly selected office hour, the number of student arrivals is 3.

Answers

Answer 1

Answer:

0.2209 = 22.09% probability that in a randomly selected office hour, the number of student arrivals is 3.

Step-by-step explanation:

We have the mean during an interval, so the Poisson distribution is used.

Poisson distribution:

In a Poisson distribution, the probability that X represents the number of successes of a random variable is given by the following formula:

[tex]P(X = x) = \frac{e^{-\mu}*\mu^{x}}{(x)!}[/tex]

In which

x is the number of sucesses

e = 2.71828 is the Euler number

[tex]\mu[/tex] is the mean in the given interval.

A statistics professor finds that when she schedules an office hour for student help, an average of 3.3 students arrive.

This means that [tex]\mu = 3.3[/tex]

Find the probability that in a randomly selected office hour, the number of student arrivals is 3.

This is P(X = 3). So

[tex]P(X = x) = \frac{e^{-\mu}*\mu^{x}}{(x)!}[/tex]

[tex]P(X = 3) = \frac{e^{-3.3}*3.3^{3}}{(3)!} = 0.2209[/tex]

0.2209 = 22.09% probability that in a randomly selected office hour, the number of student arrivals is 3.


Related Questions

Help me please with this maths question thank you

Answers

Answer:

Step-by-step explanation:

A)

The opposite sides of a rectangle are equal. The width make this obvious because both of them are x.

B)

The lengths are not so obvious, but it is never the less true. The two sides are obvious and they are therefore true.

4x + 1 = 2x + 12                   Subtract 1 from both sides.

   - 1              -1

4x = 2x + 11                         Subtract 2x from both sides

-2x   -2x

2x  =  11                               Divide by 2

x = 11/2

x = 5.5

C)

P = L + L + w + w

P = 4(5.5) + 1  + 2(5.5) + 12 + 5.5 + 5.5

P = 22 + 1 + 11 + 12 + 11

P = 23 + 23 + 11

P = 57

Find the value of y in the equation y=-4x+9 when x=-3

Answers

Answer:

y = 21

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to Right

Step-by-step explanation:

Step 1: Define

Identify

y = -4x + 9

x = -3

Step 2: Evaluate

Substitute in x [Equation]:                                                                                y = -4(-3) + 9Multiply:                                                                                                             y = 12 + 9Add:                                                                                                                   y = 21
y =21
-4x-3 =12
12+9=21

Select the correct answer. Which function is continuous across Its domain ​

Answers

Answer:

D is the answer

Step-by-step explanation:

plug the -2's in line 1 & 2 then 4 in 2 and 3

the 1&2 , and the 2 and 3 numbers have to match

Using the conditions for continuity, we find that the function D.) is continuous.

How to check if a function is continuous?

A function f(x) is said to be continuous at a point x = a, in its domain if the following three conditions are satisfied:

f(a) exists (i.e. the value of f(a) is finite)the right-hand limit = left-hand limit, and both are finite.right-hand limit = left-hand limit = f(a)

Since for -4 <= x < -2, -2 <= x < 4 and 4 <= x <= 8, the function f(x) is defined by straight lines , the function will be continuous for all x ≠ -2 and 4. Now for x = -2, 4, let us check all the three conditions:

A.

f(-2) = 0.5 * (-2)² = 2

left hand limit = -2 + 6 = 4

right hand limit = 0.5 * (-2)² = 2

Since, left hand limit is not equal to right hand limit, the function is not continuous at x = -2. No need to check further.

B.

f(-2) = 0.5 * (-2)² = 2

left hand limit = -2 -2 = -4

right hand limit = 0.5 * (-2)² = 2

Since, left hand limit is not equal to right hand limit, the function is not continuous at x = -2. No need to check further.

C.

f(-2) = 0.5 * (-2)² = 2

left hand limit = -2 + 4 = 2

right hand limit = 0.5 * (-2)² = 2

Since, left hand limit is not equal to right hand limit is equal to f(-2), the function is continuous at x = -2.

f(4) = 25 - 3*4 = 13

left hand limit = 0.5 * (4)² = 8

right hand limit = 25 - 3*4 = 13

Since, left hand limit is not equal to right hand limit, the function is not continuous at x = 4.

D.

f(-2) = 0.5 * (-2)² = 2

left hand limit = -2 + 4 = 2

right hand limit = 0.5 * (-2)² = 2

Since, left hand limit is not equal to right hand limit is equal to f(-2), the function is continuous at x = -2.

f(4) = 20 - 3*4 = 8

left hand limit = 0.5 * (4)² = 8

right hand limit = 20 - 3*4 = 8

Since, left hand limit is not equal to right hand limit is equal to f(-2), the function is continuous at x = 4.

Thus, the function is continuous.

Learn more about continuity here

https://brainly.com/question/21447009

#SPJ2

A few people gather together to play a game in which one needs to roll 3 six-sided dice. One person notices that the sum of the number of spots on three dice comes up as 11 (the event E1) more often than it does 12 (the event E2) even though it looks like it should be even. This person argues as follows: E1 occurs in just six ways:

{(1,4,6),(2,3,6),(1,5,5),(2,4,5),(3,3,5),(3,4,4)}, and E2 occurs also in just six ways: {(1,5,6),(2,4,6),(3,3,6),(2,5,5),(4,4,4),(3,4,5)}.

Therefore E1 and E2 have the same probability P(E1) = P(E2). Why isn’t it?

Answers

Answer:

Yes, P(E1)=P(E2)

Step-by-step explanation:

We are given that

Number of dice=3

Total outcomes of 1 die=6

Therefore,

Total number of outcomes =[tex]6^3=216[/tex]

E1={{(1,4,6),(2,3,6),(1,5,5),(2,4,5),(3,3,5),(3,4,4)}

E2={(1,5,6),(2,4,6),(3,3,6),(2,5,5),(4,4,4),(3,4,5)}

We have to show that E1 and E2 have the same probability P(E1) = P(E2).

Probability, [tex]P(E)=\frac{Favorable\;outcomes}{Total\;outcomes}[/tex]

Using the formula

[tex]P(E_1)=\frac{6}{216}[/tex]

[tex]P(E_1)=0.0278[/tex]

[tex]P(E_2)=\frac{6}{216}[/tex]

[tex]P(E_2)=0.0278[/tex]

Hence, P(E1)=P(E2)

Midwest Publishing publishes textbooks. The company uses an 800 number where people can call to ask questions about the textbooks and place orders. Currently, there are 2 representatives handling inquiries. Calls occurring when both lines are in use get a busy signal. Each representative can handle 12 calls per hour. The arrival rate is 20 calls per hour.

Required:
a. How many extension lines should be used if the company wants to handle 90% of the calls immediately?
b. What is the probability that a call will receive a busy signal if your recommendation in part (a) is used?
c. What percentage of calls receive a busy signal for the current telephone system with two extension lines?

Answers

Answer:

A. 18 calls

B. 0.9

C. 20

Step-by-step explanation:

Number of representatives=2,

Number of extension lines=2,

Average calls each representative can accommodate per hour = 15 calls,

Arrival rate per hour = 30 calls

(a) 90% of the arrival rate = 0.09 × 20 = 18 calls

To handle 18 calls immediately, 18 extension lines should be used

(b) Probability is given by number of possible outcomes ÷ number of total outcomes

Number of possible outcomes = 18, number of total outcomes = 20

Probability (call will receive busy signal) = 18/20 = 0.9

(c) For one extension line, numbers of calls to receive busy signal = 20 - 10 = 10 calls

Number of calls to receive busy signal for the current telephone system with two extension lines = 2 × 10 = 20 calls

First the store raised the price of a pot by 20%. Then they announced a 20% discount on the pot. Is the customer going to pay more or less for the pot now than before.

Answers

Answer:

less

Step-by-step explanation:

An increase of 20% makes the price 120% of the original price.

A discount of 20% makes the discounted price 80% of the previous price.

Original price: x

20% increase in price: 1.2 * x

20% discount over the raised price: 0.8 * 1.2 * x

Now we multiply the numbers in the last expression and compare the result with x.

0.8 * 1.2 * x = 0.96x

0.96 is less than x, so the customer pays less than the original price.

when a number is added to 1/5 of itself, the result is 24. the equation that models this problem is n+1/5n=24. what is the value of n?

Answers

+
1
5
n
=
24


5
n
+
n
5
=
24


6
5
n
=
24


n
=
24
×
5
6


n
=
20

Find the simple interest on the following. 1 ) Rs 1,760 for 3 years 6 months at the rate of 12% p.a.​

Plss help me

Answers

Answer:

739.2

Step-by-step explanation:

What is the average (with 0 decimal places) across all schools for the total score? Group of answer choices 1287 1215 1221 1229

Answers

Answer:

See explanation

Step-by-step explanation:

Required

The average

The data whose average is to be calculated are not given.

However, the formula to calculate the average is:

[tex]\bar x = \frac{\sum x}{n}[/tex]

Assume the data is:

[tex]1287\ 1215\ 1221\ 1229[/tex]

This means that the number of schools is 4

So:

[tex]\bar x = \frac{1287+ 1215+ 1221+ 1229}{4}[/tex]

[tex]\bar x = \frac{4952}{4}[/tex]

[tex]\bar x = 1238[/tex]

The average of the assumed data is 1238

Choose the algebraic description that maps the image ABC onto A'B'C'.

Answers

(X,Y-4) this is the answer to the question since the y value of the translated image is moved down from the preimage

csc(π/2) =__
a.0
b.-1
c.1
d.undefined​

Answers

Hi there!

[tex]\large\boxed{C. \text{ } 1}[/tex]

csc (π/2)

π/2 is located at (0, 1)

csc is equal to 1/y, or the reciprocal of the y-value

Therefore:

csc(π/2) = 1/1 = 1. C is the correct answer.

What is the appropriate measure of angle B?

Answers

Answer:

36.87

Step-by-step explanation:

sin(b)/12 = .05

arcsin(.6) = 36.87

We deposit $12000 into an account carning 3 % interest compounded continuously, How many years will it take
for the account to grow to $16800? Round to 2 decimal places,

Answers

Answer:

The answer is 13.33 year

Step-by-step explanation:

P = $12000

Rate = 3%

Amount = $16800

so,

I = A-P

= $16800 - $12000

= $4800

So,

T = (I × 100)/P×R

= (4800×100)/P×R

= 480000/($12000×3)

= 480000/36000

= 480/36

= 13.33 year

In the following please select whether a hypothesis test or a confidence interval is most appropriate.

a. A business owner wants to know what proportion of sales occur online for their store.
b. A book publisher wants to know if more than 25% of customers buy an entire book series all at once instead of as individual books.
c. A professor wants to know the proportion of students who regularly show up to class.
d. A researcher is interested in seeing if less than 50% of Americans support the tariffs on Chinese goods.

Answers

Answer:

A. Confidence interval

B. Hypothesis test

C. Confidence interval

D. Hypothesis test

Step-by-step explanation:

A hypothesis a hypothesis test is done in statistics whereby the person carrying out the test, tests an assumption concerning a population interval.

Confidence interval can be gotten from the statistics of observed data it provides a given range of values for a parameter that is not known.

A.we use the confidence interval here

B. We use the hypothesis test

C. The confidence interval is the appropriate test

D. The hypothesis would be best

A marketing researcher wants to test the hypothesis that, within the population, there are differences in the importance attached to shopping by consumers living in the northern, southern, eastern and western United States. Which statistical test should be used

Answers

Answer: Analysis of variance

Step-by-step explanation:

Analysis of variance is the statistical test that's used in analyzing the differences among means. The analysis of variance is used to determine if a statistically significant differences exust between the means of the independent groups.

Based on the question given, the null hypothesis will be that no difference in the importance that's attached to shopping by the consumers living in different regions in the United States.

The value of y varies with x and z, and y=8, when x=4 and z=10. What is the value of y when x=5 and z=11

Answers

n x=5 and z=12 i hope you pass

im honestly stuck in this question

Answers

The correct answer is the fourth one, as it pinpoints both dots perfectly

Nina and Amy began arguing about who did better on their tests, but they couldn't decide who did better given that they took different tests. Nina took a test in English and earned a 71.8, and Amy took a test in Social Studies and earned a 60.7. Use the fact that all the students' test grades in the English class had a mean of 71.7 and a standard deviation of 11.7, and all the students' test grades in Social Studies had a mean of 60.6 and a standard deviation of 10.5 to answer the following questions.
a) Calculate the z-score for Nina's test grade.
b) Calculate the z-score for Amy's test grade.
c) Which person did relatively better?
i. Nina
ii. Amy
iii. They did equally well.

Answers

Answer:

a) [tex]Z = 0.0085[/tex]

b) [tex]Z = 0.0095[/tex]

c)  ii. Amy

Step-by-step explanation:

Z-score:

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Question a:

Nina took a test in English and earned a 71.8. In the English class had a mean of 71.7 and a standard deviation of 11.7.

This means that [tex]X = 71.8, \mu = 71.7, \sigma = 11.7[/tex]

So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{71.8 - 71.7}{11.7}[/tex]

[tex]Z = 0.0085[/tex]

Question b:

Amy took a test in Social Studies and earned a 60.7. Students' test grades in Social Studies had a mean of 60.6 and a standard deviation of 10.5.

This means that [tex]X = 60.7, \mu = 60.6, \sigma = 10.5[/tex]

So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{60.7 - 60.6}{10.5}[/tex]

[tex]Z = 0.0095[/tex]

c) Which person did relatively better?

Amy had a higher z-score, so she did relatively better.

If you have 3/8 of one pie, what does the denominator tells you ?

Answers

Step-by-step explanation:

There was originally 8 pieces of pie.

Answer:

if you have 3/8 of one pie, the denominator tells you that the pie was divided into 8 piece.

The number of measles cases decreased by 7% to 606 cases this year. What was the number of cases prior to the increase? Express your answer rounded correctly to the nearest whole number.

Answers

Answer:

652 cases

Step-by-step explanation:

The formula for percentage increase is 100 times the final-initial/final value. If we plug the numbers in and calculate, we get 652 cases. Have a great day!

Tiham is the only striker of his team. He can catch one of the four passes delivered to him and when he get a pass he takes the shot. One of his four shots go towards the net but the goal keeper of the opposite team stop one of every two shots. What is the minimum number of passes have to be delivered to Tiham to score minimum one goal?

Answers

Answer:

1/4 *1/4*1/2 =0.03125

which as a fraction is 1/32

so the minimuim number of passes that will get him a goal is 1 since he could get it on the first try

Hope This Helps!!!

Which rations are equivalent to 30:20? check all that apply

Answers

Answer:

3:2, 6;4 hope this helps

Answer:

C, D

Step-by-step explanation:

If you multiply both numbers of a ratio by the same number, you get an equivalent ratio.

A.  Divide both numbers by 10

40:30 = 4:3 No

B. 10:0 No

C. Multiply both numbers by 10

3:2 = 30:20 Yes

D. Multiply both numbers by 5

6:4 = 30:20 Yes

Find the next number of the series 563, 647, 479, 812​

Answers

Answer:

146

Step-by-step explanation:

next number is the last -666

19. The sum of a number m and a number n, multiplied by ninety-one 20. Forty-one times the difference when six is subtracted from a num- bera 21. A number r divided by the difference between eighty-three and ten 22. The total of a number p and twelve, divided by eighteen 23. The product of a number c and three more than the sum of nine and twelve 24. The sum of a number y and ten, divided by the difference when a number x is decreased by five. I need to convert all of them into expressions. PLEASE HELP.​

Answers

Answer:

Step-by-step explanation:

19.

The numbers are m and n

Sum of m and n = m + n

Sum is multiplied by 91 = 91 x ( m + n )

20.

Let the number be = m

Six subtracted from the number = m - 6

41 times the difference = 41 x ( m - 6)

21.

Let the number be = r

Difference between 83 and 10 = 83 - 10 = 73

[tex]The \ number\ divided \ by\ the \ difference \ = \frac{r}{73}[/tex]

22.

Total of p and 23 = p + 12

[tex]Total \ divided \ by \ 18 = \frac{p + 12 }{18}[/tex]

23.

The product of c and 3  = 3c

Sum of 9 and 12 = 21

Product is more than Sum = 3c + 21

24.

Sum of y  and 10 = y + 10

Number x decreased by 5 = x - 5

[tex]Sum \ divided \ by \ difference = \frac{ y + 10 }{x - 5}[/tex]

Which pair of functions are inverses of each other?
O A. f(x) = f and g(x) = 8x?
O B. f(x) = 4 + 9 and g(x) = 4x - 9
O C. Ax) = 5x – 9 and g(x) = 149
O D. f(x) = 3 - 7 and g(x) = 247

Answers

Answer is: D

_________^__

what is the sum of the complex numbers -9-i, and -5-i?

Answers

Answer:

-14-2i

Step-by-step explanation:

-9-i+(-5-i)

collect like terms(real-real, imaginary-imaginary)

=(-9-5)+(-i-i)

=-14-2i

Give at least four different symbols that have been used to represent specific statistical measures. Describe what measure each represents.

Answers

can you show a picture of the symbols

Simplify your answer

Answers

Answer:

= F^2 x^2

Step-by-step explanation:

(F(x))^2

Apply the rule: (a) =a     (x) = x

= (Fx)^2

Apply exonent rule: (a . b)^n = a^n b^n      (Fx)^2 = F^2 x^2

= F^2 x^2

Find the interquartile range of the data set represented by this box plot.



25
20
45
35

Answers

Answer:

25

Step-by-step explanation:

im pretty sure i think only ok i think no saying bad things in the comment

25/24 as a decimal rounded to nearest hundredth

Answers

Divide 25 by 24:

25 / 24 = 1.0416

The hundredth place is the second decimal place, because the third decimal place is less than 5, the hundredths place stays the same:

Answer: 1.04

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