On a quiz there are four multiple-choice questions worth 3 points each and two true/false questions
worth 1 point each. Each multiple-choice question has five possible choices. If a student randomly
guesses on each question, what is the expected value of the student's score on the test?
a 1.8
b 5.4
c 3.4.
d 2.8
Answers
Answer:
C. 3.4
Step-by-step explanation:
We need to find expected value, which is essentially the value that we expect to get based on the amount of each "thing" at hand.
Here, we have 4 multiple-choice questions worth 3 points each and 2 true/false questions worth 1 point each. Each multiple-choice question has 5 possible answers, so the probability that you get that multiple-choice question correct is 1/5. Similarly, each true/false question has 2 possible answers, so the probability that you get that question right is 1/2.
Expected value, denoted by E(x), has the formula:
E(x) = ∑ xp(x), where x is the number of points you get per problem here and p(x) is the probability of getting the problem correct
E(x) = 4 * 3 * (1/5) + 2 * 1 * (1/2) = 12/5 + 1 = 17/5 = 3.4.
The answer is thus C.
Answer:
C. 3.4
Step-by-step explanation:
P(correct MCQ) = ⅕
P(correct T/F) = ½
4×3×⅕ + 2×1×½
2.4 + 1
3.4
Related Questions
5 hours = 2 hours + 3 hours and ____ miles = 100 miles + 150 miles
Answers
Answer:
5 hours = 2 hours + 3 hours and 250 miles = 100 miles + 150 miles
Step-by-step explanation:
100+150= 250 miles
help!!
(is only needed to answer 4 of this questions)(barinly for extra answers)
Answers
Step-by-step explanation:
if right then mark me as brainlists
6. 8/9
7. 0
8. 1/5
9. 1 1/4
10. 5/6
11. 1/5
12. 1 3/7
if i am correct please give me brainpower because i did a lot :)
can you guys help me out, asap please!!!
Answers
Answer:
85 units squared
Step-by-step explanation:
By using pythagoras' theroem, you can say a squared + b squared = c squared. If the green shape is a squared and the red is b squared, all you need to do is add the two squares together. The answer wants the answer squared so you just leave the equation answer as it is (85 unit squared) but if the equation didn't want it squared, you would need to square root the answer you it. But for this question, the answer is 85 units squared
Answer:
85 units²
Step-by-step explanation:
All sides of a square are equal.
Area of a square = x · x = x², where x = length of a side
Length of a side of the purple square = √35 = 5.92
Length of a side of the green square = √50 = 7.07
Now you can use the Pythagorean Theorem to find the length, x, of a side of the blue square.
x² = 5.92² + 7.07² = 35 + 50 = 85
x = √85 = 9.2
Therefore, area of the blue square = x² = 9.2² = 85
Approximate the correlation of the data shown below?
a.0
b.1
c.-0.8
d.-1
Answers
7th grade math I'll give brainliest
Answers
Answer:
Step-by-step explanation:
Rise over run is the slope, m
m=2/5
a) the slope is 2/5 = .4 which is below the boundary guideline. So no this is not with in carpenter's guidelines
b) the image below show a line with slope 2/5 but with intercept 3
c) the stairs can be draw on the line with rise 2 run 5 from the line. see image
d)equation is in image
2.
a) count the squares
horizontal distance =3
vertical distance =3
b) slope is vertical distance over horizontal distance so m= 3/3 =1
Use the Midpoint Rule with \(n=5\) to estimate the volume obtained by rotating about the y-axis the region under the curve \(y=\sqrt{1+x^3}\), \(0\leq x\leq 1\).
Answers
To estimate the volume using the Midpoint Rule with \(\displaystyle n=5\), we need to divide the interval \(\displaystyle 0\leq x\leq 1\) into \(\displaystyle n\) subintervals of equal width. Since \(\displaystyle n=5\), each subinterval will have a width of \(\displaystyle \Delta x=\frac{1-0}{5}=\frac{1}{5}\).
Now, let's calculate the volume using the Midpoint Rule. The formula for the volume obtained by rotating about the y-axis is:
\(\displaystyle V\approx 2\pi \sum _{i=1}^{n}y_{i}\Delta x\)
where \(\displaystyle y_{i}\) represents the value of the function \(\displaystyle y=\sqrt{1+x^{3}}\) evaluated at the midpoint of each subinterval.
First, let's find the midpoints of the subintervals. Since the width of each subinterval is \(\displaystyle \Delta x=\frac{1}{5}\), the midpoint of the \(\displaystyle i\)-th subinterval is given by:
\(\displaystyle x_{i}=\frac{\Delta x}{2}+\left( i-\frac{1}{2}\right) \Delta x=\frac{1}{10}+\left( i-\frac{1}{2}\right) \frac{1}{5}\)
Substituting \(\displaystyle x_{i}\) into the function \(\displaystyle y=\sqrt{1+x^{3}}\), we obtain:
\(\displaystyle y_{i}=\sqrt{1+\left( \frac{1}{10}+\left( i-\frac{1}{2}\right) \frac{1}{5}\right) ^{3}}\)
Now, we can calculate the approximate volume using the Midpoint Rule:
\(\displaystyle V\approx 2\pi \sum _{i=1}^{5}y_{i}\Delta x\)
Substituting the values of \(\displaystyle y_{i}\) and \(\displaystyle \Delta x\) into the formula, we can evaluate the sum and compute the estimated volume.
\(\huge{\mathfrak{\colorbox{black}{\textcolor{lime}{I\:hope\:this\:helps\:!\:\:}}}}\)
♥️ \(\large{\underline{\textcolor{red}{\mathcal{SUMIT\:\:ROY\:\:(:\:\:}}}}\)
so basically you can just tell me where the boxes go and bam you get 20 points
Answers
Step-by-step explanation:
(2/3)(-4)(9) = -24
(5/16)(-2)(-4)(-4/5)= -2
(-3/4)(7/8)=-21/32
(2 3/5) (7/9)=91/45
(5/6) x (-2)(-4) x (-4/5) -> -2
(-3/4) x (7/8) -> -21/32
(2 3/5) x (7/9) -> 91/45
what is x + 5 < 6 ? PLEASE HELP!! WILL GIVE 15 POINTS
Answers
Answer:
x < 1
Explanation:
→ x + 5 < 6
subtract both sides by 5
→ x + 5 - 5 < 6 - 5
simplify the following
→ x < 1
2. After conducting an experiment, a science student found that the force, y,
exerted by a hanging object increased as the mass of the object, X,
increased. Which scatterplot could represent the results of the experiment?
Answers
Fastest answer gets brainliest answer!
Leon is scuba diving at an elevation of −72
feet when his friend signals to come higher to see a sea turtle. Leon makes 3 ascents, each an equal distance, to reach an elevation of −18
feet, where the sea turtle is located.
What was Leon's elevation after his second ascent?
Answers
Answer: -36 feet
Step-by-step explanation:
72-18 = 54 feet ascended
54 feet / 3 ascents = 18 feet per ascent
18 feet * 2 ascents = 36 feet
-72+ 36 = -36 feet
54/3= 18, 18*2=36
72-36= 36
PLS HELP THIS IS DUE TODAY!!!
Answers
for -4 f(x)=42
for -3 f(x)=30
for -2 f(x)=20
for -1 f(x)=12
Answer:
-6: f(x)=72
-4: f(x)=42
-3: f(x)=30
-2: f(x)=20
-1: f(x)=12
Step-by-step explanation:
Hope this helps! Please vote me as Brainliest. Let me know if you need more of an explanation. Remember, cheating is never the answer. Try your best before you seek answers. Hope it's not too late. Good luck with whatever you are doing! Have an amazing day!
I know this question is not about math or science but my friends are saying the Leonardo DiCaprio when he was young is hotter than Zac Efron now and when he was young. I need y’alls opinions.
Who is hotter, young Leonardo DiCaprio or 35 year old Zac Efron? My pick is Zac Efron but I want some opinions.
Answers
Answer:
it's Zac Efron for sure, Leonardo DiCaprio is just not the same...
Help me please this is due in 4min
Answers
Answer:
3 Ib = 48 oz
16,000 lb = 8T
Step-by-step explanation:
so if you want to get 48 multiply 3 by 16
And if you want to get 8 divide 16,000 by 2000
2, 3, 5, 9, 17, 22, 31, 39
Regina kept track of the points she scored during her team’s first eight basketball games. What is Regina’s mean score?
Responses
A 3939
B 1616
C 3737
D 1313
E 17
Answers
Answer:
Mean = 16
Step-by-step explanation:
MEAN can be find bg the sum of all score divided by the amount of the score.
Mean = total amount / number of amount
Total amount = 2 + 3 + 5 + 9 + 17+ 22 + 31 + 39
= 128
number of amount = 2, 3, 5, 9, 17, 22, 31, 39
= 8
Then we can calculate mean as
Mean = 128/8
Mean = 16
2+3+5+9+17+22+31+39=128
128/8=16
In the following expression, n is a rational number: −34×(n+(−n)). Which expression is equivalent to this expression?
Answers
Answer: -34 x 0
Explanation:
n + (-n) = 0
Any number when added to itself in negative form always equals 0 (for example, 2 + (-2) = 0)
Ishi walked a total of 2 1/2 miles on the treadmill a constant rate of 4 miles per hour. Which expression shows how long in minutes ishi walked on the treadmill. Answer choices: 2.5 miles × 4miles/hour × 60minutes/1 hour. 2.5 miles ÷4miles/hour÷60minutes/1hour. 2.5 miles × 4miles/hour ÷60minutes/1hour. 2.5 miles ÷ 4miles/hour × 60minutes/1 hour
Answers
Answer:
Step-by-step explanation:
66643 step by step dm
Answer:
66643 pretty sure
Step-by-step explanation:
Please help! This really doesn't make sense to me. I NEED HELP!!!!
Answers
Find the scale of the two similar sides with known dimensions:
45/27 = 1 2/3
Figure A is 1 2/3 times larger than B. Now multiply the similar side of B to find x:
x = 18 x 1 2/3
x = 30
Answer: x = 30
Answer: 30
Step-by-step explanation:
(This is a similarity question)
So,
X/18 = 45/27
Then cross multiplication
X= 45×18/ 27
X= 30
Leanna has a rectangular piece of fabric. The fabric is 24 inches wide and 40 inches long. Leanna folds the piece of fabric along its diagonal to form a triangular scarf.
What is the area, in square inches, of the triangular scarf?
Answers
Answer:
This is a fraction equal to
30 miles ÷ 2.5 hour
Step-by-step explanation:
Answer
480
Step-by-step explanation:
Mary's Time Spent Exercising
Week 1
Sun
Week 2
0 min
Mon
0 min
45 min
Tue
45 min
45 min
Wed
40 min
Thu
45 min
50 min
50 min
Which of the following best explains why the mean is NOT an appropriate indicator of how much time Mary spends exercising on a typical day?
Fri
40 min
35 min
Sat
50 min
0 min
35 min
Answers
Answer: A I believe
Step-by-step explanation: because I said so
-10 + 13s + 7p -4s - 3p + 15 simplify it ASAP PLEASE
Answers
Answer:
4p+9s+5
Step-by-step explanation:
Jackson works as a veterinary technician and earns $12.20 per hour. Jackson normally works 40 hours a week. And a normal week, what is his total pay before taxes and other deductions
Answers
Answer:
p = 12.20h
30.5 hours
Step-by-step explanation:
Jackson works as a veterinary technician and earns per hour = $12.2
He works in a normal week = 40 hours
Let hours = h and weekly pay = p
p = 12.20h
p = $12.20 × 40
= $488.00
Last week Jackson was ill and missed some work.
His total pay before deduction was $372.10
To find the hours he work the equation will be p = 12.20h
372.10 = 12.20h
372.10/12.20 = h
h= 30.5
Do the ratios 8:9 and 4:6 form a proportion?
Answers
Answer:
No. the two ratios don't align.
Please need help ASAP.
Answers
Answer: in this order angle d, e, f line de, ef, fd
Step-by-step explanation:
GIVING 30 POINTS!
What is the least common denominator for these two fractions?
Answers
Answer:
The LCD is 12
Step-by-step explanation:
Answer: 12
Step-by-step explanation:
= -2/3 -(-3/4)
= -2/3 +3/4
= -8/12 + 9/12
so the least common denominator here will be 12 as via factorization will get 2×2×3 = 12
Here are several 3D shapes
Which are prisms?
A
B
C
D
E
Answers
Answer:
I think B C D E
Step-by-step explanation: bc there all symmetric
Kenny bought a 50-pound bag of chicken feed for $29.98 and a 25-pound bag for $15.49. Can you use proportional reasoning to find the price of a 40-pound bag? Explain.
Yes; The ratio of pounds to cost is equivalent.
Yes; The unit rates are the same.
Yes; The line containing these two points passes through the origin.
No; There is no constant of proportionality.
Answers
Answer:
No; There is no constant of proportionality.
Step-by-step explanation:
29.98 divided by 50 is 0.5996 and 15.49 divided by 25 is 0.6196. They are not proportional nor are they equal. There is a difference of 0.02.
32 ÷ 4 x (16 x 1/2) -2
Answers
32 ÷ 4 x (16 x 1/2) -2
= 32 ÷ 4 × 8 -2
= 8 × 8 - 2 = 64-2
= 62
Answer:
62
Step-by-step explanation:
32/4 x (16 x 1/2) -2
8 x 8 - 2
64-2
62
<3
IM FAILING MY MATH CLASS PLZ HELP!!!!!!!!BRAINLIEST
Dante deposits $300 to open a savings account. He will earn 2% each year on his money. If he makes no deposits or withdrawals, how much money will Dante earn in interest in 1 year? How much money will be in the account after 4 years?
What is the interest rate?
Answers
Find the value of each COMPLEMENTARY ANGLE: Angle 1: x , Angle 2: x + 40
Answers
Answer:
Angle 1 = 90 degrees
Angle 2 = 50 + 40, x = 50
The base of this pyramid is a rectangle. How many congruent faces does this pyramid have?
The pyramid has 4 congruent faces.
The pyramid has 5 congruent faces.
The pyramid has 1 pair of congruent faces.
The pyramid has 2 pairs of congruent faces.
Answers
Answer: The Pyramid has 2 pairs of congruent faces
Step-by-step explanation:
The explanation of congruent is the face has the same shape and same size. On rectangle pyramid, the height triangle are 2 same faces and 2 same faces, so it has 2 pairs of congruent faces