Answer:
[tex]E(Y)=\frac{1}{25}[/tex]
Step-by-step explanation:
Let's start defining the random variables for this exercise :
[tex]X_{1}:[/tex] '' The proportion of the particulates that are removed by the first pass ''
[tex]X_{2}:[/tex] '' The proportion of what remains after the first pass that is removed by the second pass ''
[tex]Y:[/tex] '' The proportion of the original particulates that remain in the sample after two passes ''
We know the relation between the random variables :
[tex]Y=(1-X_{1})(1-X_{2})[/tex]
We also assume that [tex]X_{1}[/tex] and [tex]X_{2}[/tex] are independent random variables with common pdf.
The probability density function for both variables is [tex]f(x)=4x^{3}[/tex] for [tex]0<x<1[/tex] and [tex]f(x)=0[/tex] otherwise.
The first step to solve this exercise is to find the expected value for [tex]X_{1}[/tex] and [tex]X_{2}[/tex].
Because the variables have the same pdf we write :
[tex]E(X_{1})= E(X_{2})=E(X)[/tex]
Using the pdf to calculate the expected value we write :
[tex]E(X)=\int\limits^a_b {xf(x)} \, dx[/tex]
Where [tex]a=[/tex] ∞ and [tex]b=[/tex] - ∞ (because we integrate in the whole range of the random variable). In this case, we will integrate between [tex]0[/tex] and [tex]1[/tex] ⇒
Using the pdf we calculate the expected value :
[tex]E(X)=\int\limits^1_0 {x4x^{3}} \, dx=\int\limits^1_0 {4x^{4}} \, dx=\frac{4}{5}[/tex]
⇒ [tex]E(X)=E(X_{1})=E(X_{2})=\frac{4}{5}[/tex]
Now we need to use some expected value properties in the expression of [tex]Y[/tex] ⇒
[tex]Y=(1-X_{1})(1-X_{2})[/tex] ⇒
[tex]Y=1-X_{2}-X_{1}+X_{1}X_{2}[/tex]
Applying the expected value properties (linearity and expected value of a constant) ⇒
[tex]E(Y)=E(1)-E(X_{2})-E(X_{1})+E(X_{1}X_{2})[/tex]
Using that [tex]X_{1}[/tex] and [tex]X_{2}[/tex] have the same expected value [tex]E(X)[/tex] and given that [tex]X_{1}[/tex] and [tex]X_{2}[/tex] are independent random variables we can write [tex]E(X_{1}X_{2})=E(X_{1})E(X_{2})[/tex] ⇒
[tex]E(Y)=E(1)-E(X)-E(X)+E(X_{1})E(X_{2})[/tex] ⇒
[tex]E(Y)=E(1)-2E(X)+[E(X)]^{2}[/tex]
Using the value of [tex]E(X)[/tex] calculated :
[tex]E(Y)=1-2(\frac{4}{5})+(\frac{4}{5})^{2}=\frac{1}{25}[/tex]
[tex]E(Y)=\frac{1}{25}[/tex]
We find that the expected value of the variable [tex]Y[/tex] is [tex]E(Y)=\frac{1}{25}[/tex]
a hamburger shop sold 360 hamburgers and a number of cheeseburgers were sold was 3 times how many were sold on Sunday?
Answer:
1080 cheeseburgers
Step-by-step explanation:
If the number of cheeseburgers are three times as many as the hamburgers, then 3x360, which is the hamburgers = 1080
I do not know what to do with the Sunday information, so perhaps the question is not complete.
Hope this helps!
I really need help , someone please help :’( ... ill also make you brainlist.
Answer:
Step-by-step explanation:A)13 miles in feet = 68640 feet
we now need to get the number of cars, we use division to get groups
68640 / 15 = 4576.
we now see there are 4576 cars in the traffic jam.
B)Less, they are longer cars so the divosor would no longer be 15, it would be a higher number. 4576 cars would not be able to fit in a 13 mile stretch if those cars were any longer.
Compute the following: Subscript 8 Baseline C Subscript 8 a. 16 b. 0 c. 64 d. 1
i think its D if im not mistaken....
13. Which of the following symbol stands for the margin of error?
A. E
B. Za/2
C.n
D.o
14. For a 95% confidence level, the confidence coefficient is ___?
A. 1.645
B. 1.96
C.2.33
D.2.585.
15.What do you call the value resulting from subtracting the margin of error from the sample mean?
A. point estimate B. interval estimate C. lower limit of the interval D. upper limit of the interval
For nos. 16-19
A survey on 200 HUMSS students of Bumasa Integrated High School shows that they read on an average of 15. 7 hour
per week. The margin of error is 2.2 hours at a 95% confidence level.
16. What is the sample mean?
A.200
B. 95
C. 15.7
D.2.2 8.
17. Which of the following values is the margin of error?
A.15.7
B. 2.2
C. 0.95 D. 0.05 9.
D.0.05 9.
Answer:
13. A
14. B
15. C
16. B
17. C
Step-by-step explanation:
Kirk used the Quantitative Reasoning Process to build a budget while he is going to college. He worked hard over the summer and saved $3,251.35 to live on during the next two semesters of school. Kirk will receive a scholarship each semester for $1,157.9. If he plans to use up all of his savings while at school, how much money can Kirk spend each month, on average, for things like groceries, entertainment, and miscellaneous items?
Assume two semesters equals 8 months total. Also assume Kirk has no other expenses than what he has listed here.
Scholarship for each Semester: $1,157.9
Tuition & Books Cost per Semester: $2,000
Housing Cost for a two-semester Contract: $1,025
If he has money left, what is the average monthly amount Kirk can afford to spend each month?
If he has overspent, what is the average monthly amount Kirk would be in debt each month?
(Indicate this amount with a negative sign)
(Round your answer to the nearest cent)
Kirk can spend $695.89 each month.
AveragesGiven that Kirk worked hard over the summer and saved $3,251.35 to live on during the next two semesters of school, and Kirk will receive a scholarship each semester for $1,157.9, to determine, if he plans to use up all of his savings while at school, how much money can Kirk spend each month, on average, for things like groceries, entertainment, and miscellaneous items, assuming two semesters equals 8 months total, the following calculation must be made:
(3251.35 + (1157.9 x 2)) / 8 = X(3251.35 + 2315.8) / 8 = X5567.15 / 8 = X695.89 = XTherefore, Kirk can spend $695.89 each month.
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Answer:
Kirk can spend $695.89 each month.
Step-by-step explanation:
The total cost of $4 sharpeners and $7 folders is $30.05. If the cost of a sharpener is $a, and a folder is $2.80 more expensive, find $a. Give your answer to two decimal places.
9514 1404 393
Answer:
a = $0.95
Step-by-step explanation:
The cost of a sharpener is 'a', and the cost of a folder is $2.80 more, so is a+2.80. The total cost of 4 sharpeners and 7 folders is ...
4a +7(a+2.80) = 30.05
11a = 10.45 . . . . . . . . . . . subtract 19.60
a = 0.95 . . . . . . . . . . . divide by 11
The cost of a sharpener is a = $0.95.
Wow! There are 51 rabbits. Round 51 to the nearest 10,
Answer:
it 50
Step-by-step explanation:
Answer:
The answer (I think) is 50.
Step-by-step explanation:
I'm a little cautious, just cause because this question seems so easy.♀️
51 is closest to 50, so 51 rounded to the nearest tenth is 50.
Could I be marked as Brainliest please???
here are 2 gold coins and 5 silver coins in Victor's coin collection. What is the ratio of the
number of silver coins to the number of gold coins?
Answer:
5:2
Step-by-step explanation:
Since we know both the number of silver and gold coins, we can put it in ratio form. Pay attention to the order; since it’s asking for silver to gold coins, the ratio would be silver:gold. We can substitute the 5 and 2 for the gold and sliver values, so we get 5:2. This answer cannot be simplified so it will stay the same.
Janet has 4 more dollars than Marta. Together they
have $38. How much does each person have?
Answer:
Janet has $21 and Marta has $17
Step-by-step explanation:
38-4 since Janet has 4 more dollars
34/2 since there are two people
17 but you still have to add the 4 to Janet since she has 4 more dollars
Answer:
Marta has $15, and Janet has $23.
Step-by-step explanation:
38 in half is 19.
19 + 4 = 23
19 - 4 = 15
lol can anyone help me asap
Answer:
A = 34.1 cm²
Step-by-step explanation:
Shape is a triangle.
Formula for area of a triangle is;
A = ½bh
In this triangle;
b is base = 11 cm
h is height = 6.2 cm
Thus;
A = ½ × 11 × 6.2
A = 34.1 cm²
Does anyone know generic rectangles?
Answer:
here you go i guess
Step-by-step explanation:
the sum of two numbers is 8. the sum of the squares of the same two numbers is 40. what are the numbers?
Answer:
The numbers are 6 and 2
Step-by-step explanation:
Given this scenario, we can set up the following equations:
x + y = 8
x² + y² = 40.
___________
x + y = 8
y = 8 – x
(y)² = (8 – x)²
y² = (8 – x)²
x² + y² = 40
x² + (8 – x)² = 40
x² + 64 – 16x + x² = 40
2x² – 16x + 64 = 40
2x² – 16x = -24
2(x² – 8x) = -24
x² – 8x = -12
x² – 8x + 12 = 0
(x – 6)(x – 2) = 0
x = 6 or 2.
x + y = 8 →
(6 or 2) + y = 8
y = 8 – (6 or 2)
y = 2 or 6.
___________
x + y = 8 →
6 + 2 = 8 →
8 = 8 ✓
x² + y² = 40 →
6² + 2² →
36 + 4 = 40 →
40 = 40 ✓
Indicate True of False for 3g > 15 Substitute 5 for g.
Answer:
False
Step-by-step explanation:
(3)(5)>15
15>15
False
y’all im struggling right now
Answer:
[tex]\frac{1}{6}[/tex]
Step-by-step explanation:
probability of getting a number greater than 4 on a die, is 2 out of 6 or [tex]\frac{2}{6} = \frac{1}{3}[/tex]
probability of getting an A on the spinner is [tex]\frac{4}{8}=\frac{1}{2}[/tex]
probability of getting both is [tex]\frac{1}{3} *\frac{1}{2} = \frac{1}{6}[/tex]
Find the missing term in the perfect-square trinomial.
____− 108y + 36
Answer: 81y^2
Step-by-step explanation: a^2-2ab+b^2=(a-b)^2 Plug values and solve.
VERY URGENT PLEASE HELP!!!!
Rafael's gas tank is 1/2 full. After he buys 9 gallons of gas, it is 4/5 full. How many gallons can Rafael's tank hold?
Answer:
30 Gallons
Step-by-step explanation:
Ok, lets see the difference the 9 gallons of gas did to Rafael's gas tank.
1/2 --> 0.5
4/5 --> 0.8
0.8-0.5 = +0.3
The tank was made 30% more full with the gas.
Next, we can use this to find the amount of gas which would need to be used to fully fill the tank, given that it was empty.
So to make it easier, say we filled it up a third of 30% to get an easier to work with 10% of fill of the gas tank.
9 / 3 ---> 3 Gallons
Now, multiply this by 10 to get the 100%
3 * 10 = 30 Gallons
All done!
HELP
What is the equation of the trend line in the scatter plot ?
Answer:
its decreasing
Step-by-step explanation:
the graph will always be read from left to right.
Can someone answer this please
Answer:
Blue
Step-by-step explanation:
A straight line has an angle of 180 on each side.
5a+18+24-a+8a-30=180
12a+12=180
12a=168
a=14
Green: 14x5+18=88
Blue:24-14=10
Yellow:8x14-30=82
A rectangular block of wood measures 5 inches wide. Over time, the width of the block of wood will shrink by 5%. A builder lets the block of wood shrink. He wants to use it to fill a gap that measures 3.5 inches wide.
How much does the builder need to cut off the wood block so that it will fit exactly in the gap? Enter the answer in the box.
The bulder needs to cut
? Inches off the block of wood.
Answer:
1.25 inches
Step-by-step explanation:
5 - 5% is 4.75
4.75 - 3.5 is 1.25
Write the slope -intercept form 3x-5y=-15
Answer: M= 3/5
Step-by-step explanation: 3/5x=3= M=3/5
Equations definitions
Answer:
Step-by-step explanation:
MEAN - a). Finds the mean of a numerical data set.
MIN - f). Finds the lowest value of a data set.
COUNT - c). Counts the number of values input for a highlighted data set
MEDIAN - d). Finds the middle value of a numerical data set
MAX - e). Finds the greatest value for a data set
SUM - g). Adds all the numbers in a highlighted range together
MODE - b). Finds the number that occurs most often in a highlighted data set.
Find the equation of the straight line which passes through (3,5) and makes y-inte
r-intercept.
Answer:
Please restate your question.
It needs the y-intercept to be decipherable.
Step-by-step explanation:
The segments shown below could form a triangle.
A. True
B. False
Answer:
true
Step-by-step explanation:
15. Find the value of x and y rounded to the nearest tenth.
X
34
45°
30°
y
Answer:
x = 24.0
y = 46.4
Step-by-step explanation:
Let opposite side = z
Using trigonometry :
Sin 30 = z / 34
z = 0.5 * 34
z = 17
We find x :
Sin 45 = 17 / x
x * sin45 = 17
x = 17 / sin 45
x = 24.04
Let y = y1 + y2
y1 = 17 / tan45
y1 = 17
y2 = 17/tan30
y2 = 29.44
y = 17 + 29.44
y = 46.44
PLEASE ASNWER ILL GIVE BRAINLIEST
Answer:
8.6
Step-by-step explanation:
a^2+b^2=c^2
7^2+5^2=c^2
49+25=c^2
74=c^2
8.6=c
Plz help me well mark brainliest if you are correct!!....
I'LL MARK YOU AS BRAINLIEST IF ANSWER CORRECT
a bookstore charges h dollars for a hardcover book, p dollars for a paperback book, and m dollars for a music CD. During a sale the store reduces the cost of of a book by 20% and reduced the cost of music CD by $1. Enter an equation for the total cost, t, for buying 5 hardcover books, 8 paperback books, and 6 music CDs during the sale.
The Equation to represent the "total-cost", "t", for purchasing "5 hardcover books", 8 "paperback-books", and 6 music CDs during the sale is t = 4h + 6.4p + 6m - 1.
The cost of the hardcover-book is = $h,
The cost of the paperback-books is = $p,
The cost for one music-CD is = $m,
In the sale, the price of each book is reduced by 20%, and
The price of music-CD is reduced by $1,
So, the cost of 5 hardcover books during the sale is:
⇒ 5h - 0.2(5h) = 4h ...because 20% = 0.2;
and the cost of 8 paperback books during the sale is:
⇒ 8p - 0.2(8p) = 6.4p,
The cost of 6 music CDs during the sale is ⇒ 6m - 1;
So, the total cost, "t", for buying 5 hardcover books, 8 paperback books, and 6 music CDs during the sale is:
⇒ t = 4h + 6.4p + 6m - 1,
Therefore, the required equation of "total-cost" is t = 4h + 6.4p + 6m - 1.
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i nedd help im almost done
If yall give me the right answer I called the branly worker to give 1,000 points to right answers so try ya best!!!
From What I understood, I need to find the area and perimeter of those shapes
Bolded words are answers
1. Triangle
Area
9*15=135
135/2=67.5
Perimeter
15+15=30
30+9=39
2. Pentagon
Area: 15.48
Perimeter: 15
Hope this Helps!
An architect wants to draw a rectangle with a diagonal of 13 centimeters. The length of the rectangle is to be 3 centimeters more than triple the width. What dimensions should she make the rectangle?
Answer:
The rectangle is 3.2 cm by 12.6 cm
Step-by-step explanation:
See attached image for a diagram.
Choose w to represent the width because the length is described by referring to the width: it's 3 more than (add 3) triple (multiplied by 3) the width.
Length = 3w + 3
The diagonal forms two right triangles, each with leg = w, other leg = 3w + 3, hypotenuse = 13.
The Pythagorean Theorem says [tex](\text{leg})^2+(\text{leg})^2=(\text{hypotenuse})^2[/tex] so
[tex]w^2+(3w+3)^2=13^2\\\\w^2+9w^2+18w+9=169\\\\10w^2+18w-160=0\\\\5w^2+9w-80=0\\[/tex]
Now solve using the Quadratic Formula with [tex]a=5,\,b=9,\,c=-80[/tex].
[tex]w=\frac{-b\pm\sqrt{b^2-4ac}}{2a}\\w=\frac{-9\pm\sqrt{81+1600}}{10}\\\\w=\frac{-9\pm\sqrt{1681}}{10}\\\\w=\frac{-9\pm41}{10}\\\\w=-5\text{ or }w=3.2[/tex]
The negative root makes no sense as a distance, so the width of the rectangle is 3.2 cm. The length is 3(3.2) + 3 = 12.6 cm.
The ages of customers in a shoe store at exactly two in the afternoon are shown in the stem and leaf plot below. Customers' Ages How many customers are under the age of 40? A. 15 B. 16 C. 10 D. 3
Answer:
A
Step-by-step explanation: