The probability distribution of a random variable X is given. x 1 2 3 4 P(X = x) 0.4 0.1 0.3 0.2 Compute the mean, variance, and standard deviation of X. (Round your answers to two decimal places.) mean variance standard deviation
Mean:
[tex]E(X) = \displaystyle \sum_{x\in\{1,2,3,4\}}x\,P(X=x) = 1\times0.4 + 2\times0.1 + 3\times0.3 + 4\times0.2 = \boxed{2.3}[/tex]
Variance:
[tex]\displaystyle V(X) = E\left((X-E(X))^2\right) = E(X^2) - E(X)^2 \\\\ E(X^2) = \sum_{x\in\{1,2,3,4\}}x^2\,P(X=x) = 1^2\times0.4 + 2^2\times0.1 + 3^2\times0.3 + 4^2\times0.2 = 6.7 \\\\ \implies V(X) = 6.7 - 2.3^2 = \boxed{1.41}[/tex]
Standard deviation:
[tex]\sigma_X = \sqrt{V(X)} = \sqrt{1.41} \approx \boxed{1.19}[/tex]
In a high school graduating class of 300, 200 students are going to college, 40 are planning to work full-time, and 80 are taking a gap year.
a. These are mutually exclusive events.
b. These are not mutually exclusive events.
c. You should add their individual probabilities.
d. None of the above are true.
PLS HELP
Find an equation of the line with a y-intercept of -3 and an x-intercept of -4.5
Answer:
y = - [tex]\frac{2}{3}[/tex] x - 3
Step-by-step explanation:
The equation of a line in slope- intercept form is
y = mx + c ( m is the slope and c the y- intercept )
Calculate m using the slope formula
m = [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex]
with (x₁, y₁ ) = (0, - 3) and (x₂, y₂ ) = (- 4.5, 0 ) ← coordinates of intercepts
m = [tex]\frac{0-(-3)}{-4.5-0}[/tex] = [tex]\frac{0+3}{-4.5-0}[/tex] = [tex]\frac{3}{-4.5}[/tex] = - [tex]\frac{2}{3}[/tex]
The line crosses the y- axis at (0, - 3 ) ⇒ c = - 3
y = - [tex]\frac{2}{3}[/tex] x - 3 ← equation of line
18. The maintenance department ordered $3,450 worth of supplies from a valve and fitting supplier. The
supplier will allow a 15% discount because of the large order. How much will the maintenance department
have to pay for the supplies?
A. $2,932.50
B. $3,398.25
C. $3,406.45
D. $2,954.50
Answer:
A) [tex]\$\ 2932.5[/tex]
Step-by-step explanation:
One is given that a certain amount of money was allotted to be spent on supplies. However, there was a discount applied to the purchase. One is asked to find the amount of money actually spent on the supplies.
$3450 was the initial price that was to be spent on supplies, however, a (15%) discount was applied to this price. Subtract (15) from (100) to find the percent value that was actually spent on supplies.
[tex]100-15=85[/tex]
(85%) of the allotted money was actually spent on supplies. Now one has to find out the numerical value of the amount spent. Divide (85) by (100) and then multiply it by the amount of money allotted to the purchase, to fin the amount actually spent on the purchase.
[tex]3450*(\frac{85}{100})\\\\=3450*0.85\\\\=2932.5[/tex]
PLEASE HELP!!!
Evaluate each expression.
(252) =
Answer:
1/5
Step-by-step explanation:
Set up and evaluate the integral that gives the volume of the solid formed by revolving the region bounded by y=x^8 and y = 256 in the first quadrant about the y-axis.
Using the shell method, the volume integral would be
[tex]\displaystyle 2\pi \int_0^2 x(256-x^8)\,\mathrm dx[/tex]
That is, each shell has a radius of x (the distance from a given x in the interval [0, 2] to the axis of revolution, x = 0) and a height equal to the difference between the boundary curves y = x ⁸ and y = 256. Each shell contributes an infinitesimal volume of 2π (radius) (height) (thickness), so the total volume of the overall solid would be obtained by integrating over [0, 2].
The volume itself would be
[tex]\displaystyle 2\pi \int_0^2 x(256-x^8)\,\mathrm dx = 2\pi \left(128x^2-\frac1{10}x^{10}\right)\bigg|_{x=0}^{x=2} = \boxed{\frac{4096\pi}5}[/tex]
Using the disk method, the integral for volume would be
[tex]\displaystyle \pi \int_0^{256} \left(\sqrt[8]{y}\right)^2\,\mathrm dy = \pi \int_0^{256} \sqrt[4]{y}\,\mathrm dy[/tex]
where each disk would have a radius of x = ⁸√y (which comes from solving y = x ⁸ for x) and an infinitesimal height, such that each disk contributes an infinitesimal volume of π (radius)² (height). You would end up with the same volume, 4096π/5.
The volume of the solid formed by revolving the region bounded by y=x^8 and y = 256 in the first quadrant about the y-axis is 4096π/5 cubic units.
What is integration?It is defined as the mathematical calculation by which we can sum up all the smaller parts into a unit.
We have a function:
[tex]\rm y = x^8[/tex] or
[tex]x = \sqrt[8]{y}[/tex]
And y = 256
By using the vertical axis of rotation method to evaluate the volume of the solid formed by revolving the region bounded by the curves.
[tex]\rm V = \pi \int\limits^a_b {x^2} \, dy[/tex]
Here a = 256, b = 0, and [tex]x = \sqrt[8]{y}[/tex]
[tex]\rm V = \pi \int\limits^{256}_0 {(\sqrt[8]{y}^2) } \, dy[/tex]
After solving definite integration, we will get:
[tex]\rm V = \pi(\frac{4096}{5} )[/tex] or
[tex]\rm V =\frac{4096}{5}\pi[/tex] cubic unit
Thus, the volume of the solid formed by revolving the region bounded by y=x^8 and y = 256 in the first quadrant about the y-axis is 4096π/5 cubic units.
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If ‘BOXES’ is OBXSE, then BOARD is
9514 1404 393
Answer:
OBADR
Step-by-step explanation:
The first two letters are swapped, and the last two letters are swapped.
BOARD . . . becomes
OBADR
The least-squares regression equation
y = 8.5 + 69.5x can be used to predict the monthly cost for cell phone service with x phone lines. The list below shows the number of phone lines and the actual cost.
(1, $90)
(2, $150)
(3, $200)
(4, $295)
(5, $350)
Calculate the residuals for 2 and 5 phone lines, to the nearest cent.
The residual for 2 phone lines is $___
The residual for 5 phone lines is $___
Answer:
First one: 2.5
Second: -6
8.5+69.5(5) = 147.5
150 - 147.5 = 2.5
8.5 + 69.5(5) = 356
350 - 356 = -6
ED2021
The residual for 2 phone lines is $2.5.
The residual for 5 phone lines is -$6.
What is the residual in a least-square regression equation?
The residual is the vertical distance separating the observed point from your expected y-value, or more simply put, it is the difference between the actual y and the predicted y.
How to solve the question?In the question, we are asked to find the residual for 2 and 5 lines using the least-squares regression equation y = 8.5 + 69.5x and the actual costs given to us.
We know that the residual is the vertical distance separating the observed point from your expected y-value, or more simply put, it is the difference between the actual y and the predicted y.
Thus for 2 phone lines:-
Actual Cost = $150.
Predicted Cost, y = 8.5 + 69.5*2 = 147.5.
Residual = Actual Cost - Predicted Cost = 150 - 147.5 = $2.5.
Thus, the residual for 2 phone lines is $2.5.
Thus for 5 phone lines:-
Actual Cost = $350.
Predicted Cost, y = 8.5 + 69.5*2 = 356.
Residual = Actual Cost - Predicted Cost = 350 - 356 = -$6.
Thus, the residual for 2 phone lines is -$6.
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simplify 7-(3n+6)+10n
Answer:
1 + 7n
Step-by-step explanation:
7-(3n+6)+10n
7 - 3n - 6 + 10 n
1 - 7n
Answered by Gauthmath
–21:(–2 – 5) + ( –14) + 6.(8 – 4.3)
If x = 1, y = 7, and z = 15, determine a number that when added to x, y, and z yields
consecutive terms of a geometric sequence. What are the first three terms in the
geometric sequence?
You're looking for a number w such that the numbers
{1 + w, 7 + w, 15 + w}
form a geometric sequence, which in turn means there is a constant r for which
7 + w = r (1 + w)
15 + w = r (7 + w)
Solving for r, we get
r = (7 + w) / (1 + w) = (15 + w) / (7 + w)
Solve this for w :
(7 + w)² = (15 + w) (1 + w)
49 + 14w + w ² = 15 + 16w + w ²
2w = 34
w = 17
Then the three terms in the sequence are
{18, 24, 32}
and indeed we have 24/18 = 4/3 and 32/24 = 4/3.
What is the remainder when () = 3 − 11 − 10 is divided by x+3
Answer:
-18/x+3
Step-by-step explanation:
1. Ewa has 20 balls of four colors: yellow, green, blue, and black. 17 of them are not green, 5 are black, and 12 are not yellow. How many blue balls does Ewa have? (Use Gaussian elimination method).
Answer:
In a bag of balls, 1/4th are green, 1/8th are blue, 1/12th are yellow and the remaining 26 are white. How many balls are blue?
There are 4 colours of balls - green, blue, yellow and white.
Add (1/4)+(1/8)+(1/12) = (6/24)+(3/24)+(2/24) = 11/24 so the balance or (24–11)/24 = 13/24 = 26 white. Hence the total number of balls are 2*24 = 48.
Of the 48 balls, green are (1/4)*48 = 12, blue are (1/8)*48 = 6, yellow are (1/12)*48 = 4 and the rest, white are 26.
Check: Total number of balls = 12+6+4+26 = 48
Answer: 6 balls are blue....
Please help‼️
Given O below, if XY and YZ are congruent, what is the measure of chord XY?
Answer:
11.2
Step-by-step explanation:
yz = 11.2
since the corresponding arc of yz and xy are same, their measures will ba same too
Answered by GAUTHMATH
Answer:
11.2
Step-by-step explanation:
good luck!
Hi! I'd appreciate if you could help me on this question.
Liam is buying bottles of soda in packages that contain 8 bottles each. If the total number of sodas Liam bough t was between 45 and 50, how many did he buy? Explain your answer.
Answer:
48
Step-by-step explanation:
We need to find the multiples of 8
8,16,24,32,40,48
48 is between 45 and 50 so he must have bought 48
Answer:
6 bottles
Step-by-step explanation:
For this question we need to know the multiple of 8 which are:
8 x 1 = 8
8 x 2 = 16
8 x 3 = 24
8 x 4 = 32
8 x 5 = 40
8 x 6 = 48
8 x 7 = 56
There is only one multiple, which is greater than 45 but less than 50, which is 8x6 l.
This means he bought 6 bottles.
Answered by g a u t h m a t h
Please helps fill in the charts
A and b
With order of pairs
Answer:
...
Step-by-step explanation:
seeee the above picture
Help me please and thank you
Step-by-step explanation:
jlejej
are u using chrome os
find lub and glb of the following set E={0.2, 0.23, 0.234, 0.2343, 0.23434, 0.234343,.....}
The lub is 0.23[tex]\mathbf{\overline{43}}[/tex], while the glb is 0.2
The given set is presented as follows;
E = {0.2, 0.23, 0.234, 0.2343, 0.23434, 0.234343,...}
The least upper bound, lub, of a set, E, is known as the supremum of the set which is the number B such that all x ∈ E are of the value x ≤ B, while there all y ∈ E has a x ∈ E such that t < x
Therefore;
The supremum, lub of the given set is 0.23[tex]\overline{43}[/tex]
The greatest lower bound, glb, b, also known as the infimum, is defined as follows;
b is the greatest lower bound if for all x ∈ E then x ≥ b
Given that b < t, then where x ∈ E, there exist a x < t
The glb of the given set is 0.2
Learn more about lub, supremum, glb, infimum, here;
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if a stone is dropped from a cliff that is 122.5m high then its height in meters after t seconds is h=122.5-4.9t^2. find its velocity after 2s
Answer:
Step-by-step explanation:
Let t = 2
h = 122.5 - 4.9·2² = 122.5-19.6 = 102.9
Surface Area of cones
Instructions: Find the surface area of each figure. Round your answers to the nearest tenth, if necessary.
9514 1404 393
Answer:
64.1 ft²
Step-by-step explanation:
The area of the cone is given by ...
A = πr(r +h) . . . . for radius r and slant height h
A = π(2 ft)(2 ft +8.2 ft) ≈ 64.1 ft²
Given the following matrices, what 3 elements make up the first column of the product matrix DA?
We have to figure out what the product of DA is,
[tex]\begin{bmatrix}-1&2&3\\8&-4&0\\6&7&1\\ \end{bmatrix}\begin{bmatrix}1\\3\\5\\ \end{bmatrix}=\begin{bmatrix}a\\b\\c\\ \end{bmatrix}[/tex]
We know that,
[tex]\begin{bmatrix}a&b&c\\d&e&f\\g&h&i\\\end{bmatrix}\begin{bmatrix}x\\y\\z\\\end{bmatrix}=\begin{bmatrix}ax+by+cz\\dx+ey+fz\\gx+hy+iz\\\end{bmatrix}[/tex]
So,
[tex]a=-1\cdot1+2\cdot3+3\cdot5=-1+6+15=20[/tex]
[tex]b=8\cdot1+(-4)\cdot3+0\cdot5=8-12=-4[/tex]
[tex]c=6\cdot1+7\cdot3+1\cdot5=6+21+5=32[/tex]
So the solution is,
[tex]a,b,c=\boxed{20,-4,32}[/tex]
Hope this helps :)
Given the linear function f(x) 2/3x + 6 evaluate f(-6)
the answer is on the photo
____________ is/are when data is analyzed in order to make decisions about the population behind the data.
A. Experiments
B. Simulations
C. Surveys
D. Statistics
Answer:
statistics are when data analyzed in order to make decisions about the population behind the data.
The correct answer to the question is Statistics (Option D).
What is statistics?
Statistics is a field of study in mathematics which deals with raw data. It is a tool which refines the data to produce meaningful results and a pathway to better understanding of it.
Some examples of raw data can be population sample which loves to see a particular TV show or a sample of students getting so and so marks in Math test.
Data is analyzed mainly by three different measure of central tendency that is mean, median and mode.
Mean is the average value of given discrete data.Median is the middle value when the data is sorted in ascending or descending order.Mode is the value that has highest frequency.Therefore, Statistics the correct answer.
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Please help me to find this answer
Step-by-step explanation:
angle of a triangle is 180, therefore to get the remaining one, subtract the sum of the two knows from 180, also for the second one; angle on a straight line is as well 180, since you have fine the interior one, subtract it from 180 to get the second answer
Answer:
so angles in a triangle add up to 180,
32+50+m<MQP=180
82+m<MQP=180
m<MQP=180-82
=98°
and angles on a straight line add up to 180 therefore
m<MQR=180-m<MQP
=180-98
=82
I hope this helps and if you don't understand feel free to ask
Help please!??!!?!?
9514 1404 393
Answer:
a) CP = SP/1.1
b) CP = $59.50
c) GST = $5.95
Step-by-step explanation:
a) Divide by the coefficient of CP.
SP = 1.1×CP
CP = SP/1.1
__
b) Use the formula with the given value.
CP = $65.45/1.1 = $59.50
__
c) You can do this two ways: subtract CP from SP, or multiply CP by 0.1.
GST = SP -CP = $65.45 -59.50 = $5.95
GST = CP×0.10 = $59.50 × 0.10 = $5.95
Find the length of FT
Step-by-step explanation:
Hey there!
From the given figure;
Angle FVT = 43°
VT = 53
Taking Angle FVT as reference angle we get;
Perpendicular (p) = FT = ?
Base (b) = VT = 53
Taking the of tan;
[tex] \tan( \alpha ) = \frac{p}{b} [/tex]
Keep all values and simplify it;
[tex] \tan(43) = \frac{ft}{53} [/tex]
0.932515*53 = FT
Therefore, FT= 49.423.
Hope it helps!
Answer:
A. 49.42
Step-by-step explanation:
tan 43 = FT ÷ VT
0.932515086 = FT ÷ 53
49.42 = FT
Find the quotient of 90 over -10
90/-10
= 9/-1
= -9
So, -9 is the quotient.
Please help me solve the question...
Answer:
All of area is πr²
Step-by-step explanation:
and we should write the area kind of radian. So if all area is π*(12)²= 144π - this for 360°- and 240° is 96π
but we must add area of the triangle which has two same side and has 6 high so it's area is 6*12√3/2 = 36✓3
our answer is 96π+ 36✓3
2. Write the equation of the line in point-slope form.
(-1,3) and (2,9)
Answer:
y - 9 = 2 (x - 2)
Step-by-step explanation:
y2 - y1 / x2 - x1 9 - 3 / 2 - (-1) 6/3 = 2
y - 9 = 2 (x - 2)
Triangle DEF has sides of length x, x+3, and x−1. What are all the possible types of DEF?
Triangle DEF is scalene
Must click thanks and mark brainliest
The triangle DEF will be a scalene triangle as all the sides of the triangle are unequal.
What is a scalene triangle?A scalene triangle is a type of triangle which have all the sides to be unequal and similarly, all the angles will also be unequal to each other.
Given that:-
Triangle DEF has sides of length x, x+3, and x−1it is given that all the sides of the triangle are x, x+3, and x−1 we can clearly see that for any value of x all the three sides will have different values. we can conclude from this that the triangle DEF is a scalene triangle.
Therefore triangle DEF will be a scalene triangle as all the sides of the triangle are unequal.
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