Answer:
To find the variance just take the second moment and subtract that from the first moment squared
To find the standard deviation just take the square root of the variance
Step-by-step explanation:
David has available 240 yards of fencing and wishes to enclose a rectangular area.
(a) Express the area A of the rectangle as a function of the width W of the rectangle.
(b) For what value of W is the area largest?
(c) What is the maximum area?
Answer:
Below in bold.
Step-by-step explanation:
Perimeter = 2*width + 2*length
So
240 = 2w + 2l
120 = w + l
l = 120 - w
(a) Area = w*l
Substituting for l:
A = w(120 - w)
A = 120w - w^2
(b)
Finding the derivative:
A = 120w - w^2
A' = 120 - 2w
For a maximum area A' = 0, so:
120 - 2w = 0
2w = 120
w = 60 yards for maximum area.
(c)
Maximum area
= 120*60 - 60^2
= 3600 yd^2.
Find the mean birth weight of these 29 babies
Answer:
The mean is 6.14
Step-by-step explanation:
Given
See attachment
Required
The mean
Mean is calculated as:
[tex]\bar x = \frac{\sum fx}{\sum f}[/tex]
So, we have:
[tex]\bar x = \frac{5 * 4 + 10 * 6 + 14 * 7}{29}[/tex]
[tex]\bar x = \frac{178}{29}[/tex]
[tex]\bar x = 6.14[/tex]
GIVING OUT BRAINLIEST HELP PLEASE ❤️
Answer:
C
Step-by-step explanation:
Christen returned an overdue book to the library. Her fine was the same as the amount on the following day. Out of the fines shown below, which one would be closest to the number of days overdue?
Answer: 21 days overdue
Explanation: Since her fine was same as the amount on the following day. 21 will be closest to the number of day overdue so it is 21 days.
Answer:
22
Explanation:
They are saying that it has to be the closest number to the number of days overdue, cannot be neither 10 nor 14, and it cannot be 18 because that's one day from the days it's been overdue, and the question is saying: Her fine was the same as the amount on the following day. The graph shows us that it is about 1 more day than 18, so the only reasonable answer here is 22.
Also, I got it correct on edg =)
In the following distribution, P(X<2) = 0.35, and expected value is 1.9
X 0 1 2 3 4
P(X) 0.10 A 0.35 B C
Required:
a. Use the fact that P(X< 2) = 0.35 to find the value of A.
b. Determine the value of B.
c. Determine the value of C.
Solution :
We have :
X 0 1 2 3 4
P(X) 0.10 A 0.35 B C
a). P(X < 2) = 0.35
P(X < 2) = P(X = 0) + P(X = 1) = 0.35
⇒ 0.10 + A = 0.35
⇒ A = 0.25
So the value of A is 0.25
b). The total probability = 1
So ,
0.10 + A + 0.35 + B + C = 1
0.10 + 0.25 + 0.35 + B + C = 1
B + C = 1 - 0.70
B + C = 0.30 ......(i)
We have the expected value = 1.9
So, [tex]$\sum X P(X) = 19$[/tex] for x = 0, 1, 2, 3, 4
⇒ (0 x 0.10) + (1 x 0.25) + (2 x 0.35) + (3 x B) + (4 x C) = 1.9
⇒ 0 + 0.25 + 0.70 + 3B + 4C = 1.9
⇒ 3B + 4C = 1.9 - 0.95
⇒ 3B + 4C = 0.95 ...................(ii)
From (i), we take the value of B = 0.30 - C and substitute it in the equation (i), we get,
⇒ 3( 0.30 - C) + 4C = 0.95
⇒ 0.90 - 3C + 4C = 0.95
⇒ C = 0.95 - 0.90
= 0.05
Now substituting the value of C = 0.05 in (ii), we get,
⇒ B = 0.05 = 0.30
⇒ B = 0.25
c). The value of C is 0.05
3
5
6) through: (-3, -3), perp. to y=-**-4
5
A) y = 2x + B) y=--x+ 2
*
3
C) y=-x+2 D) y=-x+ 2
5
3
Step-by-step explanation:
answer in the image above
the fraction 6/10 is equivalent to which of the following? 12/24 or 24/40 or 3/6 or 16/20
Answer:
24/40
Step-by-step explanation:
You can multiply both the numerator and denominator by any number
Option #3: Lets multiply by 1/2 since when you multiply 6*1/2 it equals 3 and that is the same numerator as option #3 and so now let's do the same again to the denominator 10*1/2 equals 5 and that is NOT equal to 6 in the denominator for option #3 and you can't get 3 any other way than multiplying by 1/2 (same as *.5) and so it is wrong.
Now since we know how to do it I'll just do the math for the rest.
Option 1:
6/10
6*2/10*2
12/20 and that doesn't match so it's wrong.
Option 2:
6/10
6*4/10*4
=
24/40
It matches so it's correct let's try option 4 just to check.
Option 4:
6/10
6*2/10*2
12/20
that doesn't match so it's wrong (you could have tried multiplying by decimals by I doubt you are there to that kind of math yet.)
Answer: 24/40
The width of a rectangle is 2 less than twice its length. If the area of the rectangle is 72 cm, what is the
length of the diagonal?
The length of the diagonal is
cm.
Give your answer to 2 decimal places.
Answer:
Step-by-step explanation:
W=2L-2
A=72
LW=72
L(2L-2) = 72
2L^2 -2L= 72
2L^2 -2L-72=0
L^2 - L -36 = 0
L= -5.52 or 6.52(neg # not a solution)
W=11.04
L=6.52
DIAG = [tex]\sqrt{11.04^2+6.52^2}[/tex] = 12.82
~~~~~~~~~~~~~~
Question 20
A transformer has 500 turns in its primary coil and 200 in the secondary coil.
a) If an AC voltage of 220 V and frequency 50 Hz is established in the primary coil, find the voltage
and the frequency induced in the secondary coil. (2)
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Answer:
88 V50 HzStep-by-step explanation:
The secondary voltage is proportional to the primary voltage. The constant of proportionality is the ratio of secondary turns to primary turns.
The secondary voltage is ...
(200/500)(220 V) = 88 V
__
A transformer does not change the frequency.* The voltage in the secondary coil is still 50 Hz.
_____
* Most transformers are designed to operate as linear devices. It is possible to design a transformer (with special core material) that operates non-linearly, and/or that is "tuned" to a frequency other than the one exciting the primary. That is, the secondary voltage may be some harmonic of the primary voltage. This would be a relatively unusual application of a transformer, beyond the apparent scope of the question here.
Use the following formula for compound interest. If P dollars is invested at an annual interest rate r (expressed as a decimal) compounded n times yearly, the amount A after t years is given by
A= P(1+ r/n)^nt
Required:
What rate of interest is required so that $1000 will yield $1900 after 5 years if the interest rate is compounded monthly?
Answer:
12.906%/year
Step-by-step explanation:
Given data
Principal= $1000
Final Amount= $1900
Time= 5 years
The compound interest formula is given as
A= P(1+ r/n)^nt
Solving for rate r as a decimal
r = n[(A/P)1/nt - 1]
r = 12 × [(1,900.00/1,000.00)1/(12)(5) - 1]
r = 0.12906
Then convert r to R as a percentage
R = r * 100
R = 0.12906 * 100
R = 12.906%/year
cho tứ giác lồi ABCD và điểm S không thuộc mặt phẳng(ABCD). có bao nhiêu mặt phẳng qua S và hai trong số bốn điểmA B C D
Step-by-step explanation:
Có 7 mặt phẳng
5 mặt phẳng của hình chóp S.ABCD và (SAC), (SBD)
Cậu nên hỏi trên mấy web Việt Nam thì hơn tại đa số mấy người ở đây toàn nước ngoài ạ
A landscaper buys 1 gallon of plant fertilizer. He uses 1/5 of the fertilizer, and then divides the rest into 3 smaller bottles. How much does he put in each bottle?
Answer:
4/15 gallon per bottle
Step-by-step explanation:
First, we find the remaining fraction of fertilizer after using 1/5. Using our fraction calculator, we see:
1 - 1/5 = 4/5
To find the amount of fertilizer per bottle, we then divide 4/5 by 3 and we get:
4/15 gallon per bottle
Hello, please I bed urgent help with this math problem please
Answer:
option C
Step-by-step explanation:
[tex]4c^2 + 7c - 5 = 0 , \ where \ a = 4 , \ b = 7 , \ x = - 5[/tex]
[tex]c = \frac{- b \pm \sqrt{b^2 - 4ax }}{2a} \\\\c = \frac{- 7 \pm \sqrt{49 - ( 4 \times 4 \times - 5 )}}{2 \times 4} \\\\c = \frac{- 7 \pm \sqrt{49 + 80}}{8} \\\\c = \frac{- 7 \pm \sqrt{49 + 80}}{8} \\\\c = \frac{- 7 \pm \sqrt{129}}{8} \\\\[/tex]
Answer:
Option C
Step-by-step explanation:
Quadratic formula:
[tex]4c^{2} +7c-5=0[/tex]
[tex]a=4\\b=7\\x=-5[/tex]
[tex]c=\frac{-b\frac{+}{} \sqrt{b^2-4ax}}{2a}[/tex]
[tex]c=\frac{-7\frac{+}{}49-(4*4*-5) }{2*4}[/tex]
[tex]c=\frac{-7\frac{+}{}\sqrt{129} }{8}[/tex]
hope this helps....
Find the value of k, if (x - 2) is a factor of the polynomial p(x) = 2x2 + 3x - k
Answer:
The value of k is 14.
Step-by-step explanation:
(x - 2) is a factor of the polynomial
[tex]x - 2 = 0 \rightarrow x = 2[/tex]
This means that [tex]p(2) = 0[/tex]
p(x) = 2x² + 3x - k
[tex]p(2) = 2(2)^2 + 3(2) - k[/tex]
[tex]0 = 8 + 6 - k[/tex]
[tex]14 - k = 0[/tex]
[tex]k = 14[/tex]
The value of k is 14.
how much greater is the volume of the refrigerator than the volume of the top part
Answer:
volume quantity is hjaj
Create a tree diagram that shows all the possible outcomes for tossing a coin and spinning a spinner with six equal sections numbered 1 through 6.
Step-by-step explanation:
We can use a tree diagram to help list all the possible outcomes.
probability tree coin dice
From the diagram, n(S) = 12
This may help you....
plzzz mark me as brainlist....
4 pillows and 5 quilts cost £53, 6 pillows and 5 quilts cost £57, find the cost of one each
Answer:
p=2
q=9
Step-by-step explanation:
4p+5q=53
6p+5q =57
In 8 days, a group of workers can plant 72 acres.
What is their rate in acres per day
Helppp fastttt
Answer:
Step-by-step explanation:
72/8 = 9 acres per day
A,B and C are the vertices of a triangle,
A has coordinates (4,6)
B has coordinates (2,-2)
C has coordinates (-2,-4)
D is the midpoint of AB.
E is the midpoint of AC.
prove that DE is parallel to BC.
Answer:
SSS (side, side, side)
hope it helps:))!!!
Can I have help I am stuck on this problem It would mean the world if u helped me and tysm!! =-)
Answer:
27.5 miles per gallon
1 full tank = 15.45 gallons
27.5 x 15.45 = 424.875 miles
rounded to the nearest 100th: 424.88 miles
nearest 10th: 424.9 miles
nearest whole #: 425 miles
i need help plz help me
Answer:
a+2b
Step-by-step explanation:
2(a+2b)-a-2b
2a+4b-a-2b
=a+2b
Answer:
Step-by-step explana:2 ( a+ 2b) - a- 2b
=2a + 4b - a - 2b= a + 2b
Kaya babysits to add money to her savings. She draws a graph to show how much she can earn by babysitting. What is the equation of Kaya's line in slope-intercept form
Answer:
Step-by-step explanation:
Question
At a certain university, intramural volleyball is chosen as an activity by 50% of the student population. How likely is it that a
randomly chosen student will or will not participate in intramural volleyball?
Answer:
50%
Step-by-step explanation:
50% of the student population chooses instramural volleyball, meaning 50% doesn't. So if a random student is chosen, then it is a 50% chance that they will choose volleyball and 50% chance they won't.
b. If you take one spin, what is your expected value?
Answer:
3/7
Step-by-step explanation:
Expected Value:
3(1/7) + 1(2/7) + 0(2/7) - 1(2/7) = 3/7
Expected value when we take one spin = 3/7
What is the expected value?It is the sum of values multiplied by their respective probabilities.
How do we calculate the expected value after one spin?We have 2 red, 2 purple, 2 yellow, and 1 blue sector.
Total number of Sectors = 7
∴Probability of landing on red sector = 2/7
∴Probability of landing on purple sector = 2/7
∴Probability of landing on yellow sector = 2/7
∴Probability of landing on blue sector = 1/7
Points on blue sector = 3, on yellow sector = 1, on purple sector = 0, and on red sector = -1.
X 3 1 0 -1
P(X) 1/7 2/7 2/7 2/7
Expected Value = ∑X.P(X)
=3.(1/7) + 1(2/7) + 0(2/7) - 1(2/7)
= 3/7
Learn more about Expected Values on
https://brainly.com/question/15858152
#SPJ2
The following data represents the number of days absent and the final grade for a sample of college students in a general education course at a large state university.
No. of absences 0 1 2 3 4 5 6 7 8 9
Final Grade 89.2 86.4 83.5 81.1 78.2 73.9 64.3 71.8 65.5 66.2
a) Which variable is the explanatory variable?
b) Draw a scatter plot and describe your scatter plot (Direction, Strength, Form).
c) Compute the correlation coefficient
d) Does a linear relation exist between the number of absences and the final grade? Justify your answer.
e) Write out the least-squares regression line equation.
f) Compute and draw the residual (on your scatter plot) for a student who misses 5 class meetings.
g) Explain the slope in context.
h) Is the y-intercept meaningful in this situation? Explain.
i) Compute and interpret the coefficient of determination.
j) Construct a residual plot to verify the requirements of the least-squares regression model.
please help. question in picture
Answer:
Step-by-step explanation:
You are ordering a new home theater system that consists of a TV, surround sound system, and DVD player. You can choose from 66 different TVs, 1212 types of surround sound systems, and 1818 types of DVD players. How many different home theater systems can you build
Answer:
You can build 1296 different home theater systems.
Step-by-step explanation:
Fundamental counting principle:
States that if there are p ways to do a thing, and q ways to do another thing, and these two things are independent, there are p*q ways to do both things.
There are:
6 different TVs
12 types of surround sound systems.
18 types of DVD players.
How many different home theater systems can you build?
The components are independent, so, by the fundamental counting principle:
6*12*18 = 1296
You can build 1296 different home theater systems.
Solve the system by graphing. Write the solution as an ordered pair.
y = 13x + 2
y = –x – 2
PLEASE HELP!!!!!
Answer:
the answer to the question is - 2 over 7 and - 12 over 7
|x+2|+4=11
A) x=5,-9
Answer:
the mod always gives positive answers
so the answer will be
Step-by-step explanation:
x+2+4=11
x+6=11
x=11-6
x=5
answer is x is 5
Answer:
x=5,9
Step-by-step explanation:
|x+2|+4=11
|x+2| = 7
next you get two answers by adding two or subtracting two. SO the right answer should be 5 and 9. A is wrong . I DONT SEE THE OTHER ANSWER CHOICES BUT THIS IS WHAT I GOT.
If f(x) = x2 – 2x, find:
f(-3) = [?]
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Answer:
15
Step-by-step explanation:
Put the value where the variable is and do the arithmetic.
f(-3) = (-3)² -2(-3) = 9 +6
f(-3) = 15
15
Step-by-step explanation:
f(-3)=(-3)^2 - 2(-3)
= 9 + 6 = 15
