A person takes a multiple-choice exam in which each question has five possible answers. Suppose that the person has no idea about the answers to three of the questions and simply chooses randomly for each one.
Required:
a. What is the probability that the person will answer all three questions correctly?
b. What is the probability that the person will answer exactly two questions correctly?
c. What is the probability that the person will answer exactly one question correctly?
d. What is the probability that the person will answer no questions correctly?
e. Suppose that the person gets one point of credit for each correct answer and that 1/3 point is deducted for each incorrect answer. What is the expected value of the person’s score for the three questions?
Answer:
a. 0.008 = 0.8% probability that the person will answer all three questions correctly.
b. 0.096 = 9.6% probability that the person will answer exactly two questions correctly.
c. 0.384 = 38.4% probability that the person will answer exactly one question correctly.
d. 0.512 = 51.2% probability that the person will answer no questions correctly.
e. The expected value of the person’s score for the three questions is -0.2.
Step-by-step explanation:
For each question, there are only two possible outcomes. Either the person answers it correctly, or they do not. The probability of a person answering a question correctly is independent of any other question. This means that the binomial probability distribution is used 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.
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.
[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]
And p is the probability of X happening.
Each question has five possible answers.
Person has no idea which option is correct, so the probability of answering correctly is:
[tex]p = \frac{1}{5} = 0.2[/tex]
Three questions:
This means that [tex]n = 3[/tex]
a. What is the probability that the person will answer all three questions correctly?
This is [tex]P(X = 3)[/tex]. So
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 3) = C_{3,3}.(0.2)^{3}.(0.8)^{0} = 0.008[/tex]
0.008 = 0.8% probability that the person will answer all three questions correctly.
b. What is the probability that the person will answer exactly two questions correctly?
This is [tex]P(X = 2)[/tex]. So
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 2) = C_{3,2}.(0.2)^{2}.(0.8)^{1} = 0.096[/tex]
0.096 = 9.6% probability that the person will answer exactly two questions correctly.
c. What is the probability that the person will answer exactly one question correctly?
This is [tex]P(X = 1)[/tex]. So
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 1) = C_{3,1}.(0.2)^{1}.(0.8)^{2} = 0.384[/tex]
0.384 = 38.4% probability that the person will answer exactly one question correctly.
d. What is the probability that the person will answer no questions correctly?
This is [tex]P(X = 0)[/tex]. So
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 0) = C_{3,0}.(0.2)^{0}.(0.8)^{3} = 0.512[/tex]
0.512 = 51.2% probability that the person will answer no questions correctly.
e. Suppose that the person gets one point of credit for each correct answer and that 1/3 point is deducted for each incorrect answer. What is the expected value of the person’s score for the three questions?
The expected number of correct answer is:
[tex]E(X) = np = 3*0.2 = 0.6[/tex]
And the expected number of wrong answers is 3 - 0.6 = 2.4. So, the expected score is:
[tex]S(x) = 0.6 - \frac{2.4}{3} = 0.6 - 0.8 = -0.2[/tex]
The expected value of the person’s score for the three questions is -0.2.
For the point P(2,-14) and Q(9,-9) find the distance d(P,Q) and the coordinates of the midpoint M of the segment PQ
Answer:
Step-by-step explanation:
Distance : [tex]\sqrt{(x2-x1)^2 + (y2 - y1)^2} = \sqrt{(9-2)^2 + (-9+14)^2}= \sqrt{49 + 25} = \sqrt{74}[/tex]
Midpoint :
x (m) = (2+9)/2 = 11/2
y (m) = (-14-9)/2 = -23/2
M (11/2, -23/2)
pls help I need a good grade
Answer:
D
Step-by-step explanation:
because in standard form the first number can not be greater than 10 above 10 it should be in points. e.g. D must be 6.12×10^5
Find the domain and range of the function y = √x-3 + 6
Answer:
Domain: [tex][3,\infty)[/tex]
Range: [tex][6,\infty)[/tex]
Step-by-step explanation:
I assume you mean [tex]y=\sqrt{x-3} +6[/tex]?
Take note of how x cannot be less than 3 because it would result in a negative number under the radical, which isn't real. However, x CAN be 3 because [tex]\sqrt{3-3}+6=\sqrt{0}+6=0+6=6[/tex] which is real.
Therefore, the domain of the function is [tex][3,\infty)[/tex]
As for the range of the function, we saw previously that the minimum of the domain resulted in the minimum of the range, which was 6.
Therefore, the range of the function is [tex][6,\infty)[/tex]
See attached graph below for a visual.
What’s the ara of each figure?
Answer:
433 in.²
Step-by-step explanation:
Divide the figure into 2 rectangles
Area of the figure = area of the bigger rectangle + area of smaller rectangle
✔️Area of bigger rectangle = L*W
L = 29 in.
W = 13 in.
Area of the bigger rectangle = 29*13
= 377 in.²
✔️Area of the smaller rectangle = L*W
L = 7 in.
W = 8 in.
Area of the bigger rectangle = 7*8
= 56 in.²
✅Area of the figure = 377 + 56 = 433 in.²
Nancy ate 34 ounces of cake. How much cake did she eat?
A. 1.500 lb.
B. 2.125 lb.
C. 2.500 lb.
D. 2.750 lb.
Nancy ate 34 ounces of cake. How much cake did she eat?
A. 1.500 lb.
B. 2.125 lb.
C. 2.500 lb.
D. 2.750 lb.
Answer:
the answer would be B: 2.125lb.
Answer: B; 2.125lb
Step-by-step explanation: 34 ounces to pounds is 2.13lb (rounded, the exact number is 2.125lb
find the probability of spinning an A 3 times
Bowl B1 contains one white and two red chips; bowl B2 contains two white and two red chips; bowl B3 contains one white and four red chips. The probabilities of selecting bowl B1, B2, or B3 are 0.3, 0.2, and 0.5, respectively. A bowl is selected using these probabilities and a chip is then drawn at random. Find:
a. P(W), the probability of drawing a white chip.
b. P(B1 Given W), the conditional probability that bowl B1 had been selected, given that a white chip was drawn.
Answer:
a) 0.3 = 30% probability of drawing a white chip.
b) 0.3333 = 33.33% probability that bowl B1 had been selected, given that a white chip was drawn.
Step-by-step explanation:
Conditional Probability
We use the conditional probability formula to solve this question. It is
[tex]P(B|A) = \frac{P(A \cap B)}{P(A)}[/tex]
In which
P(B|A) is the probability of event B happening, given that A happened.
[tex]P(A \cap B)[/tex] is the probability of both A and B happening.
P(A) is the probability of A happening.
a. P(W), the probability of drawing a white chip.
1/3(one white out of 3) of 0.3(from B1).
1/2(two white out of 4) of 0.2(from B2).
1/5(one white out of 5) of 0.5(from B3). So
[tex]P(W) = 0.3333*0.3 + 0.5*0.2 + 0.2*0.5 = 0.3[/tex]
0.3 = 30% probability of drawing a white chip.
b. P(B1 Given W), the conditional probability that bowl B1 had been selected, given that a white chip was drawn.
The probability of drawing a white chip from B1 is 1/3 out of 0.3, so:
[tex]P(B1 \cap W) = 0.3\frac{1}{3} = 0.1[/tex]
Then the conditional probability is:
[tex]P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{0.1}{0.3} = 0.3333[/tex]
0.3333 = 33.33% probability that bowl B1 had been selected, given that a white chip was drawn.
You can copy the data into Excel by highlighting the data, right-clicking and selecting Copy, then opening Excel, clicking on a blank cell, and selecting Paste from the Edit menu. Give your answers to at least 3 decimal places accuracy. Keep the data in Excel and keep the answers below handy, as you will need this information again in later questions. 2. Compute the following summary statistics a) The mean for the low income group is: b) The median for the low income group is: c) The standard deviation for the low income group is: d) The mean for the high income group is: e) The median for the high income group is: f) The standard deviation for the high income group is:
Answer:
Low income group :
Mean = 22.100
Median = 22.000
Standard deviation = 4.717
High Income group :
Mean = 19.771
Median = 20.000
Standard deviation = 3.255
Step-by-step explanation:
Low income : 19,20,13,28,21,27,16,21,19, 19,34,24, 24,14,24,25,23,22,20,21,14,23,17,26,24,24,20,24,27,16,22,17,29,20,25,22,20,34,24,22
High Income : 23 19 19 18 20 18 17 25 13 24 25 17 21 19 17 22 22 15 19 23 19 23 22 20 20 20 13 21 16 13 21 24 23 21 20
Using Excel :
Mean of low income, Σx / n = 884/40 = 22.100
Median of low income group : 1/2(n+1)th term = Median of low income = 22.000
Standard deviation of low income group :
√(Σ(x - mean)²/n) = 4.717
High Income group :
Mean of high income, Σx / n = 692/35 = 19.771
Median of high income group : 1/2(n+1)th term = Median of high income = 20.000
Standard deviation of low income group :
√(Σ(x - mean)²/n) = 3.255
What is the volume of the cone in the diagram?
Answer:
471.24
Step-by-step explanation:
V=πr2h/3
radius = 5 and length = 18
answer = 471.24
please mark me brainliest!!
Answer:
The answer Plato wants is 150Pi,
Step-by-step explanation:
Question 21
Find the volume.
Answer:
C
4712 cm³ exactly
Step-by-step explanation:
10² * pi is the area of the circle
then just multiply with the height
Answer:
C. 1500π ≈ 4710 cm³
Step-by-step explanation:
Volume = πr²h
Volume = π * 100 * 15
Volume = 1500π ≈ 4710 cm³
If my answer is incorrect, pls correct me!
If you like my answer and explanation, mark me as brainliest!
-Chetan K
What is 10 percent in 66
Mr. Suh puts $1,500.00 into savings bonds that pay a simple interest rate of 2.5%. How much money will the bonds be worth at the end of 10 years?
Answer:
i have no idea
Step-by-step explanation:
please answer both questions thanks
Answer:
1. tan(65) = x/3
x = 3tan(65)
= 6.434
≈ 6.4
(nearest 10th)
2. cos(43) = AB/17
AB = 17cos(43)
= 12.433
≈ 12.43
(nearest 100th)
what does this function show at x=1?
A. removable discontinuity
B. Jump discontinuity
C. Infinite discontinuity
D. Continuity
Answer:
c
Step-by-step explanation:
yeah tha answer is c I can't explain it rn but for now put c
i hat is the slope 6/-10 and 3/-13
Answer:
1
Step-by-step explanation:
Assuming your mean we have the points
(6, -10) and ( 3, -13)
We can use the slope formula
m = (y2-y1)/(x2-x1)
m = ( -13 - -10)/( 3 - 6)
= (-13+10)/( 3-6)
= -3 / -3
= 1
Pls Help I will give brianleist
Answer:
Solution given:
side1=2units
side2=8units
height[h]=6units.
now
area of trapezoid=½h(side1+side2)=½*6(8+2)=
30units².
how many liters of a 40% alcohol solution must be mixed with a 65% solution to obtain 50 L of a 50% alcohol solution
Step-by-step explanation:
Question 264138: How many liters of a 40% alcohol solution must be mixed with a 65% solution to obtain 20 liters of a 50% solution? x=8 gallons of 65% solution is used. 20-8=12 gallons of 40% solution is used.
please mark as brainliest
The following functions give the populations of four towns with time tt in years.
(i) P=600(1.12)^t
(ii) P=1,000(1.03)^t
(iii) P=200(1.08)^t
(iv) P=900(0.90)^t
Which town has the largest percent growth rate? What is the percent growth rate?
Solution :
Transforming given equations :
[tex]1)\ P = 600( 1 + \dfrac{12}{100})^t\\\\2)\ P = 1000( 1 + \dfrac{3}{100})^t\\\\3)\ P = 200( 1 + \dfrac{8}{100})^t\\\\4)\ P = 900( 1 - \dfrac{10}{100})^t[/tex]
From above equations we can see that equation 1) has largest percentage growth rate and the percent growth rate is 12% .
Hence, this is the required solution.
Answer: (i), 12%
Step-by-step explanation:
Given
The Population of four towns is given
(i) [tex]P=600(1.12)^t[/tex] i.e.
[tex]\Rightarrow P=600(1+0.12)^t\\\Rightarrow P=600(1+12\%)^t[/tex]
rate=12%
(ii) [tex]P=1000(1.03)^t[/tex]
[tex]\Rightarrow P=1000(1+0.03)^t\\\Rightarrow P=1000(1+3\%)^t[/tex]
rate=3%
(iii) [tex]P=200(1.08)^t[/tex]
[tex]\Rightarrow P=300(1+0.08)^t\\\Rightarrow P=300(1+8\%)^t[/tex]
rate=8%
(iv) [tex]P=900(0.90)^t[/tex]
[tex]\Rightarrow P=900(1-0.10)^t\\\Rightarrow P=900(1-10\%)^t[/tex]
rate=10% fall
So, the largest growth rate is for town (i) i.e. 12%
If a normal distribution has a mean of 104 and a standard deviation of 6, what is the z-score for a value of 110?
A. 1.5
B. 2
C. 1
D. 0.5
Answer: 1.5
mean: 104
S.D: 6
110-104/6=1.5
Mason randomly chooses a card from a standard deck of playing cards. What is the probability that it is not an ace, given it is a red card
Answer:
there are 52 cards in a deck so the chance is a red card (or not a red card) is 26 out of 52.
Step-by-step explanation:
The solution is 12/13
The probability that the selected card is not an ace but a red card is 12/13
What is Probability?
The probability that an event will occur is measured by the ratio of favorable examples to the total number of situations possible
The value of probability lies between 0 and 1
Given data ,
Let the probability of the selected card is not an ace but a red card be P
Now , the equation will be
Mason randomly chooses a card from a standard deck of playing cards
So , the probability that the card is a red card is
There are 26 red cards in the deck of 52 cards
So , the probability of selecting a red card = 26/52
Now , from the 26 red cards , the probability that the card is not an ace would be = 26 - ( Ace of hearts + Ace of diamonds )
And ,
The probability of the selected card is not an ace but a red card P = 24/26
The probability of the selected card is not an ace but a red card P = 12/13
Therefore , the value of P is 12/13
Hence , the probability is 12/13
To learn more about probability click :
https://brainly.com/question/17089724
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In Triangle QRS, Angle R is a right angle, m angle Q = 57° and QS = 35. Which of the following expressions correctly
calculates the length of line QR ?
9514 1404 393
Answer:
(3) 35·cos(57°)
Step-by-step explanation:
The relevant trig relation is ...
Cos = Adjacent/Hypotenuse
For the given triangle, this is ...
cos(57°) = QR/QS
Multiplying by QS gives ...
QS·cos(57°) = QR
Filling in the value of QS, we have ...
QR = 35·cos(57°)
in a function hall chairs were arranged in 20 rows and 15 columns on day 1 the next day same chairs were arranged in different numbers of rows and colums
Answer:
What exactly is the question?? u only gave the statement -_-
Step-by-step explanation:
true or false m angle 1 <m angle 7
Answer:
False
Step-by-step explanation:
There might be a chance I am wrong though sorr for the inconvinience
Grace examines two different size bottles of the same laundry detergent. The price for the 100100100-ounce bottle is \$9.99$9.99dollar sign, 9, point, 99 and the price for the 150150150-ounce bottle is \$12.99$12.99dollar sign, 12, point, 99. How much money will Grace save per 100100100 ounces if she purchases the larger bottle
Answer:
$1.33
Step-by-step explanation:
Determine the cost per ounce of the larger bottle
cost per ounce = cost of larger bottle / total ounces
$12.99 / 150 = $0.0866
Multiply cost per ounce by 100
$0.0866 x 100 = $8.66
Subtract the above figure from 9.99
9.99 - $8.66 = $1.33
Suppose you wanted to find a critical test statistic for a confidence interval for the slope of the regression line. How many degrees of freedom would you need to use?
Answer:
See Explanation
Step-by-step explanation:
The question is incomplete, as the regression line is not given.
However, I will give a general explanation of how to calculate the degree of freedom of a slope of regression line
The degree of freedom is calculated using:
[tex]df = n - k[/tex]
Where
[tex]k \to number\ of\ parameters[/tex]
[tex]n \to sample\ size.[/tex]
For a regression line; there are two parameters that are being estimates;
The intercept and the slope. So:
[tex]k = 2[/tex]
Hence, the degree of freedom of a slope of regression line is:
[tex]df = n -2[/tex]
So; if for example
[tex]n =101[/tex]
the degree of freedom will be:
[tex]df =101 - 2[/tex]
[tex]df =99[/tex]
Find the area of the polygon shown. Enter the number into the box.
m 2
2 mi
10 mi
4 mi
12 mi
1
2
Answer:
See Explanation
Step-by-step explanation:
The question is incomplete, as the image of the polygon is not given.
I will answer this question with the attached image (similar to your question)
The attached polygon is a trapezoid of the following dimensions.
[tex]Height = 4ft[/tex]
Parallel sides
[tex]Side\ 1 = 4ft[/tex]
[tex]Side\ 2 = 4ft+1ft = 5ft[/tex]
So, the area is:
[tex]Area = \frac{1}{2} * (Side\ 1 + Side\ 2) * Height[/tex]
[tex]Area = \frac{1}{2} * (4ft + 5ft) * 4ft[/tex]
[tex]Area = \frac{1}{2} * 9ft * 4ft[/tex]
[tex]Area = 18ft^2[/tex]
Wei has 150.00 to make a garland using 60-cent balloons
Answer:
The answer is 0.60b + 0.30w = 150; 60 + 0.30w = 150
Step-by-step explanation:
5th grade math. correct answer will be marked brainliest
Answer: How are we going to point it?
Step-by-step explanation:
5/6+3/9 in the simplest form
HELP PLSS
Answer:
1 1/6
Step-by-step explanation:
5/6 + 3/9
Simplify 3/9 by dividing the top and bottom by 3
5/6 + 1/3
Get a common denominator of 6
5/6 + 1/3 *2/2
5/6 + 2/6
7/6
Rewriting
6/6 +1/6
1 1/6