You receive an A 40% of the time, a B 20% of the time, a C 15% of the time , and a D the rest of the time. For any random test, what is your expected grade point average? (Use the following values for X: A=4, B=3, C=2, D=1)
The grade you receive on a test is a discrete random variable with probability mass function
[tex]f_X(x)=P(X=x)=\begin{cases}0.4&\text{for }X=4\text{ (i.e. scoring an A)}\\0.2&\text{for }X=3\text{ (B)}\\0.15&\text{for }X=2\text{ (C)}\\0.25&\text{for }X=1\text{ (D)}\\0&\text{otherwise}\end{cases}[/tex]
where the probability of getting a D is 25% because there are only 4 possible grades, and the probabilities must sum to 1 :
0.4 + 0.2 + 0.15 + 0.25 = 1
The expected test score/GPA is then
[tex]\displaystyle\sum_x x\,f_X(x)=\sum_{x=1}^4 x\,P(X=x)=1\cdot0.25+2\cdot0.15+3\cdot0.2+4\cdot0.4=\boxed{2.75}[/tex]
so your average would fall between a B and a C.
cos(0)=2/2 ,and <0<2pi, evaluate sin(0) and tan(0). sin (0)=? tan(0)=?
PLEASE HELP!!!!
Answer:
Step-by-step explanation:
The angle is between 3pi/2 and 2pi so it is in the fourth quadrant where both sin and tan are negative.
Given cos(θ) = sqrt(2)/2
cos^2(θ) + sin^2(θ) = 1
sine^2(θ) = 1 - 2/2^2 = 1 - 1/2 = 1/2
sin(θ) = +/1 sqrt(2)/2
As we know sin(θ) is negative,
sin(θ) = -sqrt(2)/2; the second answer
tan(θ) = sin(θ)/cos(θ) = -1
Answer:
Step-by-step explanation:
using (cosθ)^2 + (sinθ)^2 = 1
2/4 + (sinθ)^2 = 1
sinθ = [tex]\sqrt{2}/2[/tex]
or -[tex]\sqrt{2} /2[/tex]
By C-A-S-T, sinθ is -ve
sinθ = -[tex]\sqrt{2}/2[/tex]
tanθ = sinθ/cosθ = -1
Plz help I need it!!!!!!!!!!!!
Answer:
114°
Step-by-step explanation:
[tex]? = \frac{1}{2} (53 \degree + 175 \degree) \\ \\ ? = \frac{1}{2} \times 228 \degree\\ \\ ? = 114 \degree[/tex]
In a bag there are 3 red marbles, 2 yellow marbles and 1 blue marble. After a marble is selected, it is replaced. After 40 attempts at drawing two marbles from the bag, there were three instances where a blue marble then a yellow marble was pulled. What is the percent difference between the theoretical probability and the experimental probability?
75%
26%
56%
35%
Answer:
35%
Step-by-step explanation:
The percent error can be found using the
|Experimental value - Theoretical value| divided by |Theoretical value| and multiplied by 100.
I hope this helps
Here, the experimental probability is 1/4 and theoretical probability is 1/18.Then the percent difference between the theoretical probability and the experimental probability is 56%.
What is probability ?The probability is a measure of chances that an event to take place.
Given that,
red marbles = 3
blue marbles =1
yellow marbles = 2
Then.
theoretical probability of selecting a blue marble followed by a yellow marble is:
P(blue and yellow) = P(blue) x P(yellow) = (1/6) x (2/6) = 1/18
Since the marbles are replaced after each draw, the probability of this event is the same for every draw.
The experimental probability of selecting a blue marble followed by a yellow marble after 40 attempts is:
(3/6) x (2/6) x (40 attempts) = 10
Therefore, the experimental probability is 10/40 = 1/4
The percent difference between the theoretical probability and the experimental probability is:
| (experimental probability - theoretical probability) / theoretical probability | x 100%
= | (1/4 - 1/18) / (1/18) | x 100%
= 0.583 x 100%
= 58.3%
Therefore, the percent difference between the theoretical probability and the experimental probability is approximately 58.3%, which is closest to the option 56%.
Find more on probability ?
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Malala is following this recipe for bread rolls.
She uses 400 g of flour.
How much of the other ingredients does she use?
Recipe: Makes 12 bread rolls
600 g flour
12 g salt
9 g yeast
42 mL oil
330 mL water
400
10
7
40
130
(not sure if this helped but yeah)
What's the answer to this one?
Answer:
b^(-6)
Step-by-step explanation:
The numerator of this fraction is b^(-11). The -11 is the sum of -4 and -7.
The denominator is b^(-5).
Recall that b^a / b^c = b^(a - c). Thus, b^(-11) / b^(-5) = b^(-6)
Dylan invested some money into his bank.
He agreed a simple interest rate of 3% per annum for a period of 2 years
At the end of the 2 years period the value of his investment increased by 72%
Work out the value Dylan initial investment was?
Answer:
the initial investment is $1,200
Step-by-step explanation:
The computation of the initial investment is shown below:
As we know that
Let us assume the investment be 100
So, the investment increased be 72
So,
Simple interest = Principal × rate of interest × time period
72 = Principal × 3% × 2 years
So, the principal is
= 72 ÷ 3% × 2
= $1,200
hence, the initial investment is $1,200
Find the surface area of the pyramid, round to the nearest tenth:
Answer:
2 2/3 rounded to ten is 3 so 3 is your anser
Step-by-step explanation:
i think you multypliy 4 by 6/9 thenround
Answer:
71.2
Step-by-step explanation:
2(4)(6.9) + 4^2
What are the coordinates of the point (-1, 5) when it is reflected across the y-axis? *
Answer:
1,5
Step-by-step explanation:
when reflecting across y-axis it'll be in the same order, but using whatever form that quarter of the coordinate plane is in (e.g. 5,7 ----> -5,7)
How many square feet of outdoor carpet will we need for this hole?
Answer:
30 square ft
Step-by-step explanation:
Find the area of each rectangle and add them together
(2)(5) + (2)(6) + (2)(4) = 30
During April, he charges $387.92 to the card, and at the end of April, he makes a payment of $400.00. What will be the new balance on his card?
a) What type of triangle is triangle ABC?
b) Give reasons for your answer.
Answer:
1. isosceles
2. isosceles have 2 sides that are the same length this is the same as the tringle in the picture.
Step-by-step explanation:
Pls give me brainliest
Answer:
It is isosceles triangle
Step-by-step explanation:
The steps in the above photo
There are some small cubes and some large cubes in a bag.
The cubes are red or the cubes are yellow.
The ratio of the number of small cubes to the number of large cubes is 4:9
The ratio of the number of red cubes to the number of yellow cubes is 3:5
a) What is the least possible number of cubes in the bag?
b) work out the least number of large yellow cubes in the bag.
Answer:
Step-by-step explanation:
Remark
What a wonderful problem. I've never seen one quite like it.
Red to Yellow
The Red to Yellow ratio is given as 3:5
The total number of Red and yellow is something to 8. You get that just by adding the ratio. Let's check it out.
The reds are 3 to 8 and the yellows are 5 to 8.
Does that make sense? 3/8 + 5/8 = 8/8. All the cubes are accounted for.
Small to Large
The given ratio is 4:9
The smalls are 3/13 and the large are 9/13
3/13 + 9/13 equal 13/13 and all the cubes are accounted for.
What is the least possible number that will accomplish this?
8 * 13 is the very least number that will accomplish this. How come?
Because you have two conditions that must be met -- size and color. No other number will work. Any other number will leave a remainder when you put color and size together. So the smallest number you can use is 104,
Last question: Least Number of Large Yellows
The color yellow is 5/8
The size is Large 9/13
So the calculation is
5/8 * 9 / 13 * 104
= 5 * 9
= 45
Notice that the 8 and 13 cancel out. You are left with the number of Yellows and Large =45
Note
I'll leave the other 3 combinations to you. They should add up to 104.
3/8 * 9/13 * 104 = 27
5/8 * 4/13 * 104 = 20
3/8 * 4/13 * 104 = 12
You buy 11 bagels with a $20 bill. How much change do you receive
Answer:
You would receive $13.75
Step-by-step explanation: What i did was divided 7.50 by 6 so it would give me the price of 1 bagel(1.25).I subtracted 11 and 6 which would give me 5 so I know how much I need to calculate with the discount. Then I multiplyed 5 times 1.25 (6.25) so I could get the price for 5 bagels. After I added 7.50 and 6.25 which would give you your answer of $13.75.
I hope this helps and makes sense to you. Please mark brainlist!
plss help if u do u get brainlist and help asap school bitterly almost done
Answer:
w+8²
p+30÷p²
4(9+y)
Step-by-step explanation:
Answer:
Answers are below.
Step-by-step explanation:
1. [tex]C^{3}[/tex]
2. A + C / 3
Second exercise:
1. w + (8 x 2)
2. 30 + p / p
3. 4 (9 + y)
hope this helps and is right :) p.s. i really need brainliest.
if my answers are wrong, then i am incredibly sorry!
a school chooses 3 randomly selected athletes from each of its sports teams to participate in a survey about athletics at
the school. what type of sample is this?
A.) Simple Random Sample
B.) Stratified Random Sample
C.) Cluster Random Sample
D.) Systematic Random Sample
E.) None of the above
Since the school chooses 3 randomly selected athletes from each of its sports teams, this is a B. Stratified Random Sample.
A stratified random sample refers to a method of sampling which has to do with the division of a population into strata which are smaller groups. This is done in order to make the sampling easier.Stratified Random Sample is different from the Simple Random Sampling where one has to choose from the members. In this case, everyone has an equal chance of being selected.In this case, since the school chooses 3 randomly selected athletes from each of its sports teams, it means the stratified random sample is used.
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If f(x) = 3^(x + 4), find f(2).
Answer:
18
Step-by-step explanation:
PLEASE HELP I WILL GIVE BRAINIEST. What is the Median?
Answer:
DA MIDDLE LINE. 6
These four numbers are plotted on a number line: −2/3, 5/8, −3/5, −1/2 Which is the correct ordering on the number line, from left to right?
Answer:
i dont know too i was here seeing if you got an answer.1
Step-by-step explanation:
pls answer this people!!
Answer:
-2/3, -3/5, -1/2, 5/8
Step-by-step explanation:
The larger the number/fraction/decimal is as a positive number, the smaller it will be as a negetive.
Megan has a baseball card collection containing 10 cards. She graph the value of these 10 cards on a scatterplot as shown
Answer:
a basketball card generally increases in value over time (second one)
Step-by-step explanation:
1. it doesn't always increase
3.No it would be around 0.75
4.No it would be around $5.50 I think
hii please help i’ll give brainliest
Answer: -(-3)
Step-by-step explanation:
a double negative would equal to a positive :)
Please answer correctly! I will Mark you Brainliest!
which equation is equivalent to 5(d+1)
Answer:
5d + 5
Step-by-step explanation:
Answer:
.............5d+5
The vertex of this parabola is at (-5, 4). Which of the following could be its
equation?
(-5, 4)
A. y* -(x + 5)2 - 4
B. y = -(x - 5)2 - 4
C. y = -(x - 5)2 + 4
D. y = -(x + 5)2 + 4
Answer:
D
Step-by-step explanation:
Because the x-coordinate of the vertex is negative, only A or D could be the correct equation for this parabola. D is correct because its constant (4) matches the y-coordinate of the vertex (-5, 4).
Answer:
y = -(x + 5)2 + 4
Step-by-step explanation:
simplify the ratio 25:15:10
Answer:
60%
Convert fraction (ratio) 15 / 25 Answer: 60%
Suppose that y varies directly with x
and y=
= 10 when x = 20. What is y
when x = 15?
Be sure to simplify your answer.
Answer:
[tex]10 \times 2 = 20 \\ 5 \times 3 = 15[/tex]
answer:10×2=20
5×3=15
Answer:
y = 7.5
Step-by-step explanation:
Given y varies directly with x then the equation relating them is
y = kx ← k is the constant of variation
To find k use the condition y = 10 when x = 20
10 = 20k ( divide both sides by 20 )
[tex]\frac{1}{2}[/tex] = k
y = [tex]\frac{1}{2}[/tex] x ← equation of variation
When x = 15 , then
y = [tex]\frac{1}{2}[/tex] × 15 = [tex]\frac{15}{2}[/tex] = 7.5
2) Byron made a scale model of his
favorite car. The car is 14 feet long.
Byron's model is 3.5 inches long. What
is the scale Byron used to make his
model car?
9514 1404 393
Answer:
1 : 48
Step-by-step explanation:
The scale is ...
3.5 in : 14 ft = 3.5 in : 168 in = 1 : 48
Answer:
Solution :-At first we need to convert ft into in
1 ft = 12 in
14 × 12 = 168 inches
Ratio = 3.5 : 168
Ratio = 1:48
[tex] \\ [/tex]
Mhanifa can you please help?
Answer:
Question 5Sum of angles of a regular polygon is 360°
If one angle is 8°, then number of sides is:
360°/8° = 45Question 4Sum of interior angles of a polygon with n sides:
180°(n - 2) = 5400°n - 2 = 30n = 32Exterior angle measure is:
360°/32 = 11.25°Question 13Sum of exterior angles is 360°
Each exterior angle is:
360°/16 = 22.5°Wendy borrowed a 370-page book from the library. She has already read 20 pages. The book is due back to the library in 7 days. Write an inequality to find the number of pages per day Wendy must read in order to finish the book before it is due.
0 points
Answer:
n ≥ 50
Step-by-step explanation:
Total pages = 370
Read pages = 20
Number of days remaining = 7
Reading rate per day = n
7n + 20 ≥ 370
7n ≥ 370 - 20
7n ≥ 350
n ≥ 350/7
n ≥ 50 pages per day for the remaining 7 days
The math problem is in picture
Answer:
B
Step-by-step explanation:
Welcome for the answer!Answer:
my best guess would be B
Step-by-step explanation:
3.61 + 1.23 = 4.48