Answer: E(X) = 4
V(X) = [tex]\frac{16}{3}[/tex]
Step-by-step explanation: An uniform distribution is a random variable X restricted to a finite interval [a,b] and has a constant function f(x) over this interval, i.e., the function is of form:
f(x) = [tex]\left \{ {{\frac{1}{b-a} } \atop {0}} \right.[/tex]
The mean or expectation of an unifrom distribution is:
E(X) = [tex]\int\limits^b_a {x.f(x)} \, dx[/tex]
For the density function in interval [0,8], expectation value is:
E(X) = [tex]\int\limits^8_0 {x.(\frac{1}{8-0} )} \, dx[/tex]
E(X) = [tex]\int\limits^8_0 {\frac{x}{8} } \, dx[/tex]
E(X) = [tex]\frac{1}{8}. \int\limits^8_0 {x} \, dx[/tex]
E(X) = [tex]\frac{1}{8}.(\frac{x^{2}}{2} )[/tex]
E(X) = [tex]\frac{1}{8} (\frac{8^{2}}{2} )[/tex]
E(X) = 4
Variance of a probability distribution can be written as:
V(X) = [tex]E(X^{2}) - [E(X)]^{2}[/tex]
For uniform distribution in interval [0,8]:
V(X) = [tex]\int\limits^b_a {x^{2}.\frac{1}{8-0} } \, dx - (\frac{8+0}{2})^{2}[/tex]
V(X) = [tex]\frac{1}{8} \int\limits^8_0 {x^{2}} \, dx - 4^{2}[/tex]
V(X) = [tex]\frac{1}{8} (\frac{x^{3}}{3} ) - 16[/tex]
V(X) = [tex]\frac{1}{8} (\frac{8^{3}}{3} ) - 16[/tex]
V(X) = [tex]\frac{64}{3}[/tex] - 16
V(X) = [tex]\frac{16}{3}[/tex]
The mean and variance are 4 and 16/3, respectively
WILL MARK BRAINLIEST If Alan and Zack can clean a room in 30 minutes when working together, and Alan cleans twice as fast as Zack, how long would it take Alan to clean the room by himself?
Answer:
45 min
Step-by-step explanation:
Here,
the we take the work as W and Alan's speed as A and Zack's speed as Z.
A = 2Z
W = 30 ( A+Z)
if the time for Alan to done cleaning alone is t then t = W ÷ A
t = ( 30 (A+(A÷2)))÷ A
t = 45 min
I am done .
One kind of candy (jelly) sells for $5 a pound and another (chocolate) for $10 a pound. How many pounds of each should be used to make a mixture of 10 pounds of candy (both kinds) that sells for a total $80 (i.e. $8/pound)?
Answer:
chocolate: 6 poundsjelly: 4 poundsStep-by-step explanation:
Let x represent the number of pounds of chocolate in the mix. Then the total price of 10 pounds of mix is ...
10x +5(10 -x) = 80
5x +50 = 80
5x = 30
x = 6 . . . . . . . . pounds of chocolate
10 -x = 4 . . . . . pounds of jelly candy
6 pounds of chocolate and 4 pounds of jelly should be used to make the mixture.
Anyone Willing To Hell Out?
Z=
37
39
51
the answer is 36.36 but the closest to it is 37
Identify the correct HYPOTHESES used in a hypothesis test of the following claim and sample data:
Claim: "The average battery life (between charges) of this model of tablet is at least 12 hours."
A random sample of 80 of these tablets is selected, and it is found that their average battery life is 11.58 hours with a standard deviation of 1.93 hours. Test the claim at the 0.05 significance level.
a. H0: p = 12 vs. H1: p < 12
b. H0: ? = 12 vs. H1: ? < 12
c. H0: p = 12 vs. H1: p > 12
d. H0: ? = 12 vs. H1: ? > 12
Answer:
The null hypothesis is ;
H0 ≥ 12
While the alternative hypothesis H1 is ;
H1 < 12
Step-by-step explanation:
Here, we want to correctly identify the null hypothesis H0 and the alternative hypothesis H1
The null hypothesis is as follows ;
H0 ≥ 12
While the alternative hypothesis H1 is ;
H1 < 12
Which linear inequality is represented by the graph?
Answer:
A. y ≤ 1/2x + 2
Step-by-step explanation:
Well look at the graph,
It is a solid line with it shaded down,
meaning it is y ≤,
So we can cross out B. and D.
So the y intercept is 2, we know this because the y intercept is the point on the line that touches the y axis.
now the slope can be found by seeing how far away each points are from each other,
Hence, the answer is A. y ≤ 1/2x + 2
I hope u can understand help asap
i think u can see sho T=5n+20
Answer:
T(n) = 5n + 20
Step-by-step explanation:
1 candy has a mass of 5 g.
n candies have a mass of 5n grams.
The box has a mass of 20 grams.
total mass = mass of candies + mass of box
T(n) = 5n + 20
n T(n)
0 20
25 145
50 270
75 395
100 520
Salaries of 43 college graduates who took a statistics course in college have a mean,66,000 , of . Assuming a standard deviation, 18908 , of $, construct a %99 confidence interval for estimating the population mean .
Answer:
$[58543.42; 73456.58]
Step-by-step explanation:
Hello!
For the variable
X: salary of a college graduate that took a statistics course
Out of n= 43 students, the calculated mean is [tex]\frac{}{X}[/tex]= $66000
The population standard deviation is δ= $18908
There is no information about the variable distribution, but since the sample size is big enough (n≥30), you can apply the CLT and approximate the distribution of the sample mean to normal [tex]\frac{}{X}[/tex]≈N(μ;σ²/n)
Then you can apply the approximation of the standard normal distribution to calculate the 99% CI
[tex]\frac{}{X}[/tex] ± [tex]Z_{1-\alpha /2}[/tex] * [tex]\frac{Singma}{\sqrt{n} }[/tex]
[tex]Z_{1-\alpha /2}= Z_{0.995}= 2.586[/tex]
[tex]\frac{Singma}{\sqrt{n} }= \frac{18908}{\sqrt{43} }= 2883.44[/tex]
[66000±2.586*2883.44]
$[58543.42; 73456.58]
With a 99% confidence level you'd expect that the interval $[58543.42; 73456.58] will include the average salary of college graduates that took a course of statistics.
I hope this helps!
What is viscosity?
O A measure of the oil's quality
O An oil's resistance to flow at different temperatures
A reference to synthetic oil; all oils with viscosity are synthetic
O A new motor oil ingredient
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>
Answer:
viscosity is the state of being thick, sticky, and semifluid in consistency, due to internal friction.
"cooling the fluid raises its viscosity"
a quantity expressing the magnitude of internal friction, as measured by the force per unit area resisting a flow in which parallel layers unit distance apart have unit speed relative to one another.
plural noun: viscosities
"silicone oils can be obtained with different viscosities"
Step-by-step explanation:
The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water. hope this helps you :)
Answer:
O An oil's resistance to flow at different temperatures
Step-by-step explanation:
Internal friction of a moving fluid .
At time, t=0, Billy puts 625 into an account paying 6% simple interest. At the end of year 2, George puts 400 into an account paying interest at a force of interest, δt=16+t for t≥2. If both accounts continue to earn interest indefinitely at the levels given above, the amounts in both accounts will be equal at the end of year n. Calculate n.
Answer:
26
Step-by-step explanation:
Given that:
At time, t=0, Billy puts 625 into an account paying 6% simple interest
At the end of year 2, George puts 400 into an account paying interest at a force of interest, 1/(6+t), for all t ≥ 2.
If both accounts continue to earn interest indefinitely at the levels given above, the amounts in both accounts will be equal at the end of year n. Calculate n.
In order to calculate n;
Let K constant to be the value of time for both accounts
At time, t=0, the value of time K when Billy puts 625 into an account paying 6% simple interest is:
[tex]K = 625 \times (1+ 0.06 K)[/tex]
[tex]K = 625 +37.5 K[/tex]
At year end 2; George amount of 400 will grow at a force interest, then the value of [tex]K = 400 \times e^{\int\limits^2_k {\dfrac{1}{6+t}} \, dx }[/tex]
[tex]K =400 \times \dfrac{6+K}{6+2}[/tex]
[tex]K =400 \times \dfrac{6+K}{8}[/tex]
[tex]K =50 \times ({6+K})[/tex]
[tex]K =300+50K[/tex]
Therefore:
If K = K
Then:
625 + 37.5 = 300 +50 K
625-300 = 50 K - 37.5 K
325 = 12.5K
K = 325/12.5
K = 26
the amounts in both accounts at the end of year n = K = 26
The dot plots show the number of hours a group of fifth graders and seventh graders spent playing outdoors over a one-
week period.
Time Spent Playing Outdoors
for Fifth Graders and Seventh Graders
.
5th Grade
0
ta
1 2 3 4 5
Hours
7
8
9 10
7th Grade
.
Answer: B
Step-by-step explanation:
Answer:B
Step-by-step explanation: I took the edge quiz and it was right.
Please help. I’ll mark you as brainliest if correct!
Answer:
Quantity (lbs) of type 1 candy x = 8
Quantity (lbs) of type 2 candy y = 17,5
Step-by-step explanation:
Let´s call "x" quantity (in pounds) of candy type 1 in the mixture, and "y" quantity (in pounds ) of candy type 2, then according to the problem statement.
x + y = 25,5
2,20*x + 7,30*y = 5,70 * 25,5 ⇒ 2,20*x + 7,30*y = 145,35
Then we have a two equation system
x + y = 25,5 ⇒ y = 25,5 - x
2,20*x + 7,30*y = 145,35 ⇒ 2,20*x + 7,30* (25,5 - x ) = 145,35
2,20*x + 186,15 - 7,30*x = 145,35
5,1*x = 40,8
x = 40,8/5,1
x = 8 lbs
And y = 25,5 - 8
y = 17,5 lbs
Ash Lee bought a new Brunswick boat for $17,000. He made a $2,500 down payment on it. The bank's loan was for 60 months. Finance charges totaled $4,900. His monthly payment is:
Answer: $323.33
Step-by-step explanation:
($17,000 + $4,900 - $2,500) ÷ 60 months = $323.33 per month
↓ ↓ ↓
price finance down payment
Please help, I don’t need an explanation, just the answer.
Answer:
x=2 y=4
Step-by-step explanation:
PLEASE HELP ?
Convert by looking at the thermometer and measure to the nearest 5 degrees F.
31 degrees Celsius to Fahrenheit
Answer:
90º
Step-by-step explanation:
just look at where 31º on the right lines up with the value on the left (aka around 90º)
Answer:
87.8 °F ≈ 90°F
Step-by-step explanation:
[tex]x \ degrees \ F = 31 \ degree \ Celsius *\frac{9}{5} + 32\\x \ degrees \ F = 55.8 + 32\\\\x \ degrees \ Fahrenheit = 87.8 \ degrees \ Farenheit[/tex]
Translate the following into an algebraic expression: A number is 30% of 20% of the number x.
Answer: 0.06x
Step-by-step explanation:
An algebraic expression is an expression consist of integer constants, variables, and algebraic operations.The given statement: A number is 30% of 20% of the number x.
The required algebraic expression would be:
30% of 20% of x
[tex]=\dfrac{30}{100}\times \dfrac{20}{100}\times x[/tex] [we divide a percentage by 100 to convert it into decimal]
[tex]=\dfrac{6}{100}\times x\\\\=0.06x[/tex]
Hence, the required algebraic expression would be :
0.06x
what is this? 15.8 = d/25
Answer:
395
Step-by-step explanation:
15.8=d/25
multiply both sides by 25 to remove the denominator
25×15.8=d
d=395
What is the value of s in the equation 3 r equals 10 plus 5 s, when r equals 10? 4 8 100 200
Answer
4Step-by-step explanation:
Given,
r = 10
Let's create an equation,
[tex]3r = 10 + 5s[/tex]
plugging the value of r
[tex]3 \times 10 = 10 + 5s[/tex]
Multiply the numbers
[tex]30 = 10 + 5s[/tex]
Move 5s to L.H.S and change its sign
Similarly, Move 30 to R.H.S and change its sign.
[tex] - 5s = 10 - 30[/tex]
Calculate
[tex] - 5s = - 20[/tex]
The difference sign ( - ) should be cancelled on both sides
[tex]5s = 20[/tex]
Divide both sides of the equation by 5
[tex] \frac{5s}{2} = \frac{20}{5} [/tex]
Calculate
[tex]s = 4[/tex]
The value of s is 4.
Hope this helps..
Best regards!!
Answer:
A. 4 (on edgenuity)
Step-by-step explanation:
The amount of time to complete a physical activity in a PE class is approximately normally normally distributed with a mean of 32.9 seconds and a standard deviation of 6.4 seconds.
A) What is the probability that a randomly chosen student completes the activity in less than 33.2 seconds?
B) What is the probability that a randomly chosen student completes the activity in more than 46.6 seconds?
C) What proportion of students take between 35.5 and 42.8 seconds to complete the activity?
D) 75% of all students finish the activity in less than____seconds.
Answer:
The answer is below
Step-by-step explanation:
Given that mean (μ) of 32.9 seconds and a standard deviation (σ) of 6.4 seconds.
The z score is used to measure by how many standard deviation the raw score is above or below the mean. It is given by:
[tex]z=\frac{x-\mu}{\sigma}\\[/tex]
a) For x < 33.2 seconds
[tex]z=\frac{x-\mu}{\sigma}\\\\z=\frac{33.2-32.9}{6.4} =0.05[/tex]
From the normal distribution table, the probability that a randomly chosen student completes the activity in less than 33.2 seconds = P(x < 33.2) = P(z < 0.05) = 0.5199 = 51.99%
b) For x > 46.6 seconds
[tex]z=\frac{x-\mu}{\sigma}\\\\z=\frac{46.6-32.9}{6.4} =2.14[/tex]
From the normal distribution table, the probability that a randomly chosen student completes the activity in more than 46.6 seconds = P(x > 46.6) = P(z > 2.14) = 1 - P(z < 2.14) = 1 - 0.9927 = 0.0073 = 0.73%
c) For x = 35.5 seconds
[tex]z=\frac{x-\mu}{\sigma}\\\\z=\frac{35.5-32.9}{6.4} =0.41[/tex]
For x = 42.8 seconds
[tex]z=\frac{x-\mu}{\sigma}\\\\z=\frac{42.8-32.9}{6.4} =1.55[/tex]
From the normal distribution table, the proportion of students take between 35.5 and 42.8 seconds to complete the activity = P(35.5 < x < 42.8) = P(0.41< z< 1.55) = P(z < 1.55) - P(z < 0.41) = 0.9332 - 0.6591 = 0.2741 = 27.41%
d) A probability of 75% = 0.75 corresponds to a z score of 0.68
[tex]z=\frac{x-\mu}{\sigma}\\\\0.68=\frac{x-32.9}{6.4} \\\\x-32.9=4.4\\x=4.4+32.9\\x=37.3[/tex]
75% of all students finish the activity in less than 37.3 seconds
which values will only have one zero??
If it has a single zero that means it has to be just touching the x-axis with its tip.
We know that if it has only one zero, the discriminant equals 0.
So,
[tex]D=b^2-4ac=0\implies (-k)^2-4(1)(9)=0[/tex]
Solving for k,
[tex]k=\pm\sqrt{36}=\boxed{\pm{6}}[/tex].
Hope this helps.
Alex has built a garden shed in the shape shown.
(A) Alex plans to paint the outside of the shed, including the roof but not the floor. One can of paint can cover 6m^2 . How many cans of paint will Alex need.
(B)If one can of paint costs $25.50, what will the cost be including 13% tax.
Answer:
A) 22 cans required to paint
B) Including 13% tax, cost of painting = $633.93
Step-by-step explanation:
As we check the figure, we have a composite figure.
Cuboid on the base and a pyramid on the top of it.
To find the area to be painted, we have 4 rectangular faces of cuboid with dimensions 6m [tex]\times[/tex] 3m.
And 4 triangular faces of pyramid with Base = 6m and Height 5m.
So, total area to be painted = 4 rectangular faces + 4 triangular faces
Area of rectangle = Length [tex]\times[/tex] Width = 6 [tex]\times[/tex] 3 = 18 [tex]m^2[/tex]
Area of triangle = [tex]\frac{1}{2}\times Base \times Height =\frac{1}{2}\times 6 \times 5 = 15\ m^{2}[/tex]
Total area to be painted = 4 \times 18 + 4 \times 15 = 72 + 60 = 132 [tex]m^2[/tex]
A) Area painted by 1 can = 6 [tex]m^2[/tex]
Cans required to paint 132 [tex]m^2[/tex] = [tex]\frac{132}{6} = 22\ cans[/tex]
B)
Cost of 1 can = $25.50
Cost of 22 can = $25.50 [tex]\times[/tex] 22 = $561
Including tax of 13% = $561 + $561 [tex]\times \frac{13}{100}[/tex] = $561 + $72.93 = $633.93
So, the answers are:
A) 22 cans required to paint
B) Including 13% tax, cost of painting = $633.93
Hi I need this question please asap.
Fake Question: Should Ujalakhan01 be a moderator? (If you could answer I'd appreciate it haha.)
Real Question: Simplify [tex](a^5*a^4)+(b^2*b^3)-(c^7*c^6)[/tex]
Answer:
[tex]a^9 + b^ 5 + c^{13}[/tex]
Step-by-step explanation:
[tex](a^5 \times a^4)+(b^2 \times b^3) + (c^7 \times c^6)[/tex]
When bases are same and it is multiplication, then add the exponents.
[tex](a^{5+4})+(b^{2+3})+(c^{7+6})[/tex]
[tex](a^9)+(b^ 5) + (c^{13})[/tex]
Apply rule : [tex](a^b)=a^b[/tex]
[tex]a^9 + b^ 5 + c^{13}[/tex]
Answer:
[tex]a^9+b^5-c^{13[/tex]
Step-by-step explanation:
[tex](a^5*a^4) + (b^2*b^3)-(c^7*c^6)[/tex]
When bases are same, powers are to be added.
=> [tex](a^{5+4})+(b^{2+3})-(c^{7+6})[/tex]
=> [tex]a^9+b^5-c^{13[/tex]
McKenzie has a bag contains six red marbles four blue marbles and 14 yellow marbles if she chooses one marble from the bag what is the probability that the marble is not yellow
Answer:
5/12
Step-by-step explanation:
Total number of marbles in the bag
6red+ 4blue + 14 yellow = 24 marbles
Not yellow marbles = 10 marbles
P ( not yellow ) = number of not yellow marbles / total marbles
=10/24
= 5/12
Answer:
5/12
Step-by-step explanation:
6 red marbles
4 blue marbles
14 yellow marbles
total marbles = 6 + 4 + 14 = 24 marbles
24 - 14 = 10 marbles
10 marbles are not yellow.
P(not yellow) = 10/24 = 5/12
Question 3 (5 points)
POINT
-POINT A
POINT B
What are the coordinates of the point labeled B in the graph shown above?
A) (3, 2)
B) (-3,2)
OC) (-2,3)
D) (-2, -3)
Question 4 (5 points)
Answer:
(D) -2,-3
Step-by-step explanation:
From the origin, we can find the current position of point B by counting.
B is 2 to the left of the y-axis, meaning that it's x value is -2.
B is 3 down of the x-axis, making it's y value -3.
Therefore, the coordinates of point B are -2,-3.
Hope this helped!
Answer: (D) -2,-3
Step-by-step explanation:
A family paid $28,500 as a down payment for a home. If this represents 15% of the price of the home, what is the price of the home.
Answer:
.15* house price = 28,500
house price = 28,500 / .15
house price = 190,000
Step-by-step explanation:
Answer: 190,000
Step-by-step explanation:
the equation looks like this - .15x=28,500. then you divide both sides by .15 and get x=190,000
21.65 to 1 decimal place
Answer:
21.7
Step-by-step explanation:
When anything is 5 or above in a decimal place you round up to the next number for example
2.35 this would round up to be 2.4
21.65
Place value of 1 = ones place
Face value of 1 = 1
Note : The face value of a number will not change at all
Hope it helps you..If it's wrong plz say and I'll try to recorrect it :)
Four buses carrying 198 students from the same school arrive at a football stadium. The buses carry, respectively 90, 33, 25, and 50 students. One of the students is randomly selected. Let X denote the number of students who were on the bus carrying the randomly selected student. One of the four bus drivers is also randomly selected. Let Y denote the number of students on her bus. a) Which of E[X] or E[Y] do you think is larger
Answer:
E[x] is larger
Step-by-step explanation:
I think E[x] is larger because the expected number of students on the bus of a randomly chosen student is larger.
This is because the higher the number of students present in a bus, the higher the probability that a randomly selected student would have been on that bus.
Whereas, for every driver to be chosen, the probability of any bus being chosen is 1/4 irrespective of the number of students in that particular bus
what is 20% of 50naira?
Answer:
10
Step-by-step explanation:
To find 20% of 50 you need to times 20 with 50 and divide by 100.
20×50÷100
=10
Part of the proceeds from a garage sale was $440 worth of $10 and $20 bills. If there were 2 more $10 bills than $20 bills, find the number of each denomination.
Hey there! I'm happy to help!
Let's set this up a system of equations where x represents the number of 10 dollar bills and y represents the number of 20 dollar bills.
10x+20y=440
x=y+2
We see that x has a value of y+2, so we can replace the x in the first equation with y+2 so we can solve for y.
10(y+2)+20y=440
We use distributive property to undo the parentheses.
10y+20+20y=440
We combine like terms.
30y+20=440
We subtract 20 from both sides.
30y=420
y=14
Since there are 2 more $10 bills, there would be 16 of those.
Therefore, there are 16 $10 bills and 14 $20 bills.
Have a wonderful day! :D
Find the probability of each event. A six-sided die is rolled seven times. What is the probability that the die will show an even number at most five times?
Answer:
[tex]\dfrac{15}{16}[/tex]
Step-by-step explanation:
When a six sided die is rolled, the possible outcomes can be:
{1, 2, 3, 4, 5, 6}
Even numbers are {2, 4, 6}
Odd Numbers are {1, 3, 5}
Probability of even numbers:
[tex]\dfrac{\text{Favorable cases}}{\text{Total cases }} = \dfrac{3}{6} = \dfrac{1}{2}[/tex]
This is binomial distribution.
where probability of even numbers, [tex]p =\frac{1}{2}[/tex]
Probability of not getting even numbers (Getting odd numbers) [tex]q =\frac{1}{2}[/tex]
Probability of getting r successes out of n trials:
[tex]P(r) = _nC_r\times p^r q^{n-r}[/tex]
Probability of getting even numbers at most 5 times out of 7 is given as:
P(0) + P(1) +P(2) + P(3) +P(4) + P(5)
[tex]\Rightarrow _7C_0\times \frac{1}{2}^0 \frac{1}{2}^{7}+_7C_1\times \frac{1}{2}^1 \frac{1}{2}^{6}+_7C_2\times \frac{1}{2}^2 \frac{1}{2}^{5}+_7C_3\times \frac{1}{2}^3 \frac{1}{2}^{4}+_7C_4\times \frac{1}{2}^4 \frac{1}{2}^{3}+_7C_5\times \frac{1}{2}^5 \frac{1}{2}^{2}[/tex]
[tex]\Rightarrow (\dfrac{1}{2})^7 (_7C_0+_7C_1+_7C_2+_7C_3+_7C_4+_7C_5)\\[/tex]
[tex]\Rightarrow (\dfrac{1}{2})^7 (1+7+\dfrac{7 \times 6}{2}+\dfrac{7 \times 6 \times 5}{3\times 2}+\dfrac{7 \times 6 \times 5}{3\times 2}+\dfrac{7 \times 6}{2})\\\Rightarrow \dfrac{120}{128} \\\Rightarrow \dfrac{15}{16}[/tex]