A quiz consists of 570 true or false questions. If the student guesses on each question, what is the mean number of correct answers?

Answers

Answer 1

Answer:

285

Step-by-step explanation:

570/2=285

true or false means theres a 1/2 possibility you guess right thats why you divide by 2

Answer 2

The mean number of correct answers to 570 true or false questions will be 285.

What is the expected value?

In parameter estimation, the expected value is an application of the weighted sum. Informally, the expected value is the simple average of a considerable number of individually determined outcomes of a randomly picked variable.

The expected value is given below.

E(x) = np

Where n is the number of samples and p is the probability.

For the true or false, the probability of getting correct is given as,

p = 1/2

There are 570 true or false questions in a quiz. If the pupil guesses for each inquiry. Then the expected value is given as,

E = 570 x (1/2)

E = 285

The mean number of correct answers will be 285.

More about the expected value link is given below.

https://brainly.com/question/13945225

#SPJ2


Related Questions

Consider a taxi station where taxis and customers arrive in accordance with Poisson processes with respective rates of one and three per minute. A taxi will wait no matter how many other taxis are present. However, an arriving customer that does not find a taxi waiting leaves. Find the proportion of arriving customers that get taxis.

Answers

Answer:

The proportion of arriving customers that get taxis is:

= 33%.

Step-by-step explanation:

Rate of arrival of taxis = 1 per minute

In one hour, the number of taxis arriving = 60 (60/1)

Rate of arrival of customers = 3 per minute

In one hour, the number of customers arriving = 180 (60 * 3)

The proportion of arriving customers that get taxis = 60/180

= 0.333

= 33%

b) Since the taxis wait until they get a customer, it means that they will likely transport one out of 3 customers who arrive.  Therefore, the proportion of arriving customers that get taxis is equal to 1/3 or 60/180, which is equal to 33%.


(2 + 3x)
62
Angle Relationship: Adjacent OR Vertical

Answers

Answer:

adjacent

Step-by-step explanation:

Answer the question in the picture plz

Answers

A number raised to a fraction would be the same as a root to the inverse of the fraction.

What that means is the sqrt(8) raised to 1/4 is the same as being 4th root of 8.

So rewriting the given equation you would have cubic root 8 x 4th root 8

Combine the roots by multiplying: 3 x 4 = 12

The equivalent equation would be C. 12 root 8 ^ x

yo can someone pls help me with this i’ve been crying for the last hour bc i can’t figure it out and it’s due in 30 minutes. the question is “find the area and perimeter to this composite figure”. i will give you the most brainly if you answer and solve. thank you <3

Answers

9514 1404 393

Answer:

area: 524 cm²perimeter: 124.8 cm

Step-by-step explanation:

The rectangle in the middle has a width equal to the radius of the semicircular ends, so (20 cm)/2 = 10 cm.

The semicircular ends, together, make a complete circle of radius 10 cm.

The area is the sum of the areas of the parts:

  A = LW = (21 cm)(10 cm) = 210 cm² . . . . . . rectangle area

  A = πr² = π(10 cm)² = 100π cm² ≈ 314 cm² . . . . . circle area

The total area is ...

  210 cm² +314 cm² = 524 cm² . . . . area of the figure

__

The perimeter of the figure is the sum of the lengths of all of the edges. From the left, working clockwise, we have ...

  P = (1/2 circle of diameter 20) + (rectangle top = 21) +(1/2 circle of diameter 20) +(circle radius = 10) +(rectangle bottom = 21) +(circle radius = 10)

The two 1/2 circles add to a whole circle with a circumference of ...

  C = πd = (3.14)(20 cm) = 62.8 cm

Then the whole perimeter is ...

  P = 62.8 cm + 21 cm + 10 cm + 21 cm + 10 cm = 124.8 cm

_____

Note that we have used 3.14 for pi. If you use a more exact value, your answers will be slightly different.

The green arcs show a pair of SAME SIDE INTERIOR ANGLES.

Drag the two black points to show another pair.

Same side interior angles are:
Always congruent
Sometimes congruent
Never congruent
Explain your thinking.

Answers

It would be purple and green

15 people working 5 hours per day can make 30 units of a product in 10 days. Assuming all other factors remaining
constant and people of same efficiency are used to make the same products, in how many days can 10 people
make 10 units of the product if each of them works 10 hours per day?
SELECT ONLY ONE
2.5 days
7.5 days
12 days
26 days

Answers

The required number of days is 2.5 days

First, we need to calculate the amount of units generated per day.

If 15 people working 5 hours per day can make 30 units of a product in 10 days, then the amount of units per day is calculated as:

Units per day = (15*5*10)/30

Units per day = 750/30

Units per day = 25 units/day

If people of the same efficiency are used to make the same products, the number of days needed by 10 people to make 10 units of the product if each of them works 10 hours per day will be;

Number of days = (25*10)/10*10

Number of days = 250/100

Number of days = 2.5 days

Hence the required number of days is 2.5 days

Learn more on proportions here: https://brainly.com/question/19994681

Plz show work, NEED HELP FAST PLZ

Answers

Answer:

5. 4        6. 6

Step-by-step explanation:

Number 5

[tex]10-2\sqrt{9}[/tex]

[tex]2\sqrt{9}=6[/tex]

[tex]=10-6[/tex]

Subtract the numbers: 10 - 6 = 4

[tex]=4[/tex]

Number 6

[tex]70-\left(\sqrt[3]{64}\right)^3[/tex]

[tex]\left(\sqrt[3]{64}\right)^3=64[/tex]

[tex]=70-64[/tex]

Subtract the numbers: 70 - 64 = 6

[tex]=6[/tex]

25 - [2x(18 divided by 3) + 2

Answers

Answer:

the answer is 11

Step-by-step explanation:

if you take 18 divided by 3 and then 2 times that plus 2 and minus 25 it is 11

Ms. jones wants to take her students for all of her classes on a field trip to see a Broadway production. There are three shows to choose from. She wants to determine which show students would like to see. which sample would be the most appropriate for this survey?

A: Every fifth student that enters her classroom

B: Her Honors class

C: 5 boys in each of her class

D: At the end of the day, ask teachers what they think student will like

Answers

Answer:

A

Step-by-step explanation:

Because it is a random sample

Order the following numbers from least to greatest: 2.74, 1/9, 4^2, -2^3, 32.5%,-6

Answers

Answer:

2

3

,

6

,

1

9

,

32.5

%

,

2.74

,

4

2

Step-by-step explanation:

PLEASE HELP ME ANSWER!!!

Answers

Answer:

61.3°

Step-by-step explanation:

For angle x, 12 is the adjacent leg. 25 is the hypotenuse.

The trig ratio that relates the adjacent leg and the hypotenuse is the cosine.

cos A = adj/hyp

cos x = 12/25

x = cos^-1 12/25

x = 61.3°

Conduct the following test at the level of significance by determining ​(a) the null and alternative​ hypotheses, ​(b) the test​ statistic, and​ (c) the​ P-value. Assume that the samples were obtained independently using simple random sampling. Test whether . Sample data are ​, ​, ​, and . ​(a) Determine the null and alternative hypotheses. Choose the correct answer below. A. versus B. versus C. versus Your answer is correct.D. versus ​(b) The test statistic is nothing. ​(Round to two decimal places as​ needed.)

Answers

Answer:

Hello your question is poorly written the complete question is attached below

answer :

a) H0 : p1 = p2

  Ha : p1 ≠ p2

b)  Z = -0.58

c) P-value =  0.561915

d) we will reject the Alternative hypothesis

Step-by-step explanation:

For sample 1 ;  n1 = 254 , x1 = 28

For sample 2 ; n2 = 301 , x2 = 38

level of significance ∝ = 0.01

P1 = X1 / n1 = 28 / 254  = 0.1102

P2 = X2 / n2 = 38 / 301 = 0.126

a) Determine the null and alternate hypothesis

H0 : p1 = p2

Ha : p1 ≠ p2

b) Determine Test statistic

we perform a Z-statistic to test the hypothesis

Z = [tex]\frac{p1-p1 }{\sqrt{( p(1-p)*(\frac{1}{n1}+\frac{1}{n2}) ) } }[/tex]  -------- ( 1 )

p =  ( x1 + x2 ) / ( n1 + n2 )

= ( 28 + 38 ) / ( 254 + 301 ) = 0.1189

Where: p = 0.1189 , p1 = 0.1102 , p2 = 0.126 ( input values into equation 1 )

∴ Z = -0.58

c) Determine P-value

P-value =  0.561915 ( using excel function )

d) conclusion : since p-value > 0.01 ( level of significance ) we do not reject the null hypothesis.  therefore it proves that p1 = p2

Dana bought 144 pencils for $8.64.which equation could be used to determine the cost of each pencil,x?
A.144/8.64=x
B.x/144=8.64
C.8.64-x=144
D.144x=8.64​

Answers

Answer:

144x=8.64

This way you can divide by 144 to find how much each individual pencil costs

Someone please please help me with this!!!

Answers

Answer:

[tex]4x {}^{2} - 36 \\ = (2x + 6)(2x - 6) \\ hence \: option \: b \: is \: correct[/tex]

The length of a rectangle is 3 yards less than 5 times the width. If the perimeter is 102 yards, find the length and the width of the rectangle.

Answers

Answer:

Width = 9 yards, length = 42 yards

Step-by-step explanation:

Perimeter = 2xlength + 2xwidth. Let's call length L and width W. The question also states that L = 5W-3. Therefore, 102 = 2x (5W-3) + 2W. Then, 102 = 12W - 6. 108 = 12W, so W = 9 yards. Since L = 5W - 3, we get 45-3 = 42 yards.

W = 9 yards L= 42 yards

I WILL MARK BRAINLIEST IF CORRECT! Look at the image below.

Answers

Answer:

C 1/10 × 33

D 0.1 × 33

Hope that helps

hi can you please help me with my work​

Answers

the answer is the second one. 2 and 2/3

What is the volume of the rectangular solid below?
plzzzz help

Answers

16 cubic inchessssss

7
1. Represent these numbers on the number line. (i)7÷4​

Answers

Answer:

Answer is in picture

Step-by-step explanation:

Hope it is helpful.....

26.5 multiplied by 0.38

Answers

10.07 would be the answer

Answer:

10.07

Step-by-step explanation:

26.5 x 0.38 = 10.07

Can I get brainliest

a bakery place the following price for bagels one bagel for $1.50 two bagels for$2.25 a half a dozen for
$6.50 a dozen for $12 is the price per bagel proportion 2 the number of bagels brought.​

Answers

Answer:

no

Step-by-step explanation:

1 bagel $1.50     ---------> unit cost: $1.50/bagel

2 bagels $2.25

6 bagels $6.50

12 bagels $12    ---------> unit cost: $1/bagel

Since the unit costs are not equal, the prices are not proportional.

I NEED HELP PLZ ( WILL GIVE BRAINLIST) NO LINKS

Answers

Answer:

2 1/2

Step-by-step explanation:

i used the  lwh for this/ (length) (width) (height)

Branliest will be appreciated and thanks!

offering 19 points to whoever can solve this need the answers

Answers

Answer:

Excuse Me! I believe you forgot to add your question and or picture with the question(s) in it! I would highly recommend to re-upload your question(s) to get the desired information needed!

Yours Truely, TheAnimeCatUwU

Complete the square in the following quadratic equation

Answers

Answer:

x^2 + 2x = 1 = - 1

Step-by-step explanation:

x^2 + 2x + 3 = 1

x^2 + 2x + 3 - 2 = 1 - 2

x^2 + 2x + 1 = - 1

50 POIINTS!!!
A coin is flipped 20 times. The results are 12 heads and 8 tails. Determine the theoretical probability of getting heads.

60%
40%
20%
50%

SOMEONE PLEASE PUT STEPS TO SOLUTION.

Answers

Answer:

What we have here is experimental probability:   12 heads out of 20 tosses. The fraction 12/20 reduces to  6/10, or 0.60, which corresponds to 60%.

red die and a blue die are rolled. You win or lose money depending on the sum of the values of the two dice. If the sum is 5 or 9, you win $6. If the sum is 6, 7, or 12, you win $2. If the sum is any other value (2, 3, 4, 8, 10, or 11), you lose $4. Let X be a random variable that corresponds to your net winnings in dollars. What is the expected value of X

Answers

Answer:

The expected value of X is $0.2222.

Step-by-step explanation:

A probability is the number of desired outcomes divided by the number of total outcomes.

For each dice, there are 6 possible outcomes(values from 1 to 6). So for 2 dices, there are [tex]6^2 = 36[/tex] possible outcomes.

Desired outcomes:

Sum 5: (1,4), (2,3), (3,2), (4,1).

Sum 6: (1,5),(2,4),(3,3),(4,2),(5,1)

Sum 7: (1,6), (2,5), (3,4), (4,3), (5,2), (6,1)

Sum of 9: (3,6), (4,5), (5,4), (6,3);

Sum of 12: (6,6)

Probabilities:

4 + 4 = 8 outcomes with a sum of 5 or 9.

8/36 = 2/9 probability of a sum of 5 or 9.

12 outcomes with a sum of 6, 7 or 12.

12/36 = 1/3 probability of the sum being 6, 7 or 12.

36 - 20 = 16 outcomes in which the sum is any other value. So

16/36 = 4/9 probability of a sum of any other value.

What is the expected value of X?

2/9 probability of earning $6.

1/3 = 3/9 probability of earning $2.

4/9 probability of losing $4.

Multiplying each outcome by its probability, we find the expected value. So

[tex]E = \frac{2}{9}*6 + \frac{3}{9}*2 - \frac{4}{9}*4 = \frac{12 + 6 - 16}{9} = \frac{2}{9} = 0.2222[/tex]

The expected value of X is $0.2222.

1. Josh is reading a book that contains 100 pages. If he reads 1/3 of the book in 1/6 of an hour, how many pages per hour does Josh read?​

Answers

100/3=33.33.... 1/6= 10 mins 33.33....*6= 199.98

hope this helped you out!!

Where does the graph of f(x) = (x + 9)(x - 4) cross the x-axis?​

Answers

hi

f(x) = (x+9)  (x-4)

if it's cross the  x axis it's means  f(x) = 0

(x+9) (x-4) = 0  means   x+9 = 0  so x = -9  and   x-4 = 0 so x = 4

answers f(x) = 0 for  x = -9 and  x = 4

Who knows the answer for this problem

Answers

- Each friend has 10 nails to paint

- There are 8 friends

- Jackie finished painting 4 friend's nails

If there are 8 friends, and each friend has 10 nails to paint, then there are 80 nails that need to be painted in total.

Jackie finished painting 40 nails.

So the math sentence will be:

80 - 40 = 40

--------------------------------------------------

Jackie needs to paint 40 more nails.

A line has a slope of -5 and includes the points (-1,r) and (-2,-2). What is the value of r?

Answers

Answer:

-7

Step-by-step explanation:

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