Answer:
Step-by-step explanation:
Hello, we want to prove that a proposition depending on n, that we can note P(n), is true for any n positive integer greater than 1. We need to follow several steps.
Step 1 - prove P(1)
For n = 1, n(2n+1)=1*3 =3 so we have
3 = 3, which is obviously true.
First step done!
Step 2 - for [tex]k\geq 1[/tex] we assume P(k) and we need to prove P(k+1)
We assume that 3+7+11+...+(4k-1)=k(2k+1)
so we can write that
3+7+11+...+(4k-1)+(4(k+1)-1)=k(2k+1)+(4k+4-1)=k(2k+1)+4k+3
[tex]=2k^2+k+4k+3\\\\=2k^2+5k+3[/tex]
and
(k+1)(2(k+1)+1)=(k+1)(2k+3)
[tex]=k(2k+3)+2k+3\\\\=2k^2+3k+2k+3\\\\=2k^3+5k+3[/tex]
These two expressions are the same so it means that P(k+1) is true, meaning that
3+7+11+...+(4k-1)+(4(k+1)-1)=(k+1)(2(k+1)+1)
Step 3 - The conclusion
Finally, we have just proved that
3+7+11+...+(4n-1)=n(2n+1) for any n positive integer > 0
Thank you
The given sum of arithmetic progression series 3+7+11+... (4n-1) = n(2n+1) is true.
What is Arithmetic progression?The difference between every two successive terms in a sequence is the same this is known as an arithmetic progression (AP).
The arithmetic progression has wider use in mathematics for example sum of natural numbers.
Natural number = 1,2,3,4,5,6,7,8...
Now it has the same difference between any two consecutive terms d =2-1 = 3-2.
The Sum of n terms of an AP is given by,
S= n/2[2a + (n-1)d ] where a is first term and d is common difference.
In our series 3+7+11+... (4n-1)
First term (a) = 3
Common difference (d) = 7 - 3 = 4
So the sum will be
S = n/2[2(3) + (n-1)4]
S = n[3 + 2(n - 1)]
S = n (2n + 1 ) = Right hand side.
Hence "The given sum of arithmetic progression series 3+7+11+... (4n-1) = n(2n+1) is true".
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In this diagram, bac~edf. if the area of bac= 6 in.², what is the area of edf? PLZ HELP PLZ PLZ PLZ
Answer:
2.7 in²
Step-by-step explanation:
Given:
∆BAC ~ ∆EDF
Area of BAC = 6 in²
EF = 2 in
BC = 3 in
Required:
Area of ∆EDF
SOLUTION:
Let x = area of ∆EDF
[tex] \frac{6 in^2}{x} = (\frac{3 in}{2 in})^2 [/tex] (theorem of area of similar triangles)
[tex] \frac{6 in^2}{x} = (\frac{3 in}{2 in})^2 [/tex]
[tex] \frac{6}{x} = \frac{9}{4} [/tex]
Cross multiply:
[tex] 6*4 = 9*x [/tex]
[tex] 24 = 9x [/tex]
Divide both sides by 9
[tex] \frac{24}{9} = x [/tex]
[tex] 2.67 = x [/tex]
Area of ∆EDF = 2.7 in²
A European study of thousands of men found that the PSA screening for prostate cancer reduced the risk of a man’s dying from prostate cancer from 3.0 percent to 2.4 percent. "But it’s already a small risk. I don’t think a difference of less than 1 percent would be of practical importance," said Ed. Do you agree with Ed’s conclusion?
Answer:
Following are the answer to this question:
Step-by-step explanation:
In the given statement, we don't agree with Ed’s conclusion, because it is not relevant simply since it is not statistically significant. The reduction of prostate cancer is the death risk, which is highly significant even if it decreases significantly. It can also be something statistically important without becoming important.
Question:
A school's band members raised money by selling magazine subscriptions and shirts. Their profit from selling shirts was per shirt minus a one-time set-up fee. Their profit from selling magazine subscriptions was per subscription. They made exactly the same profit from shirts as they did from magazines. They also sold the same number of shirts as magazine subscriptions. How many shirts did they sell?
Jamie has a jar of coins containing the same number of nickels, dimes and quarters. The total value of the coins in the jar is 13.20. How many nickels does Jamie have?
The gasoline gauge on a van initially read ⅛ full. When 15 gallons of gasoline were added to the tank, the gauge then read ¾ full. How many more gallons would be needed to fill the tank?
Answer:
Question 1: 40 shirts and 40 magizines
Question 2: $4.4
Question 3: 6 gallons
Answer:
hello
Step-by-step explanation:
Write all the factors of 32
Matj
Answer
Answer: 1, 2, 4, 8, 16, and 32.
Step-by-step explanation:
Factors are what we can multiply to get the number.
Factors of 32:
1 x 32=32
2 x 16=32
4 x 8=32
Therefore, the factors of 32 are 1, 2, 4, 8, 16, and 32.
If x =y, then x-a=y-a represents the blank property of equality. A-addition B-symmetric C-subtraction D.transitive
Answer:
Subtraction property
Step-by-step explanation:
Answer:
Subtraction
Step-by-step explanation:I took the test
Jeff is playing a racing game. The game awards him an initial of virtual money. In addition, he gets of virtual money for each race he wins. In the end, he calculates average earnings of for each race he won. If represents the number of races he won, which equation can be used to find the number of wins? A. B. C. D.
Consider the function f(x) = x2. Which of the following functions shifts f(x)
downward 5 units and to the right 3 units?
A)f(x) = (x + 3)2 - 5
B) f(x) = (x - 3)2 - 5
C) f(x) = (x - 5)2 - 3
D) f(x) = (x - 5)2 + 3
Answer:
f(x) = (x - 3)² - 5
Step-by-step explanation:
equate equation to 0
(x - 3)² = 0
take the square root on both sides
x - 3 = 0
add 3
x = 3
If x = 3 then you are moving to 3 units to the right.
- 5 means you are going downward 5 units.
A video rental store keeps a list of their top 15 movie rentals each week. This week the list includes 6 action, 4 comedies, 3 dramas, and 2 mysteries. The store manager removes a copy of each of the 15 movies from the shelf, then randomly selects 3 of the 15 to show on the display monitors in the store. What is the probability that she selected 2 comedies and 1 action movie?
Answer:
32/1125Step-by-step explanation:
Probability is the likelihood or chance that an event will occur.
Probability = Expected outcome of event/Total outcome.
If a video rental store keeps a list of their top 15 movie rentals each week, the total outcome is 15.
If the list for the week includes 6 action, 4 comedies, 3 dramas, and 2 mysteries and the store manager removes a copy of each of the 15 movies from the shelf, then randomly selects 3 of the 15 to show on the display monitors in the store, the probability that she selected 2 comedies and 1 action movie will be calculated as shown;
Probability of selecting 2 comedies = 4/15*4/15 = 16/225 (Note that the expected outcome in this case is 4).
Probability of selecting 1 action movie = 6/15 = 2/5
Hence, the probability that she selected 2 comedies and 1 action movie will be equivalent to 16/225*2/5 = 32/1125
Note that the rented movies will have to be returned hence reason for the replacement.
What is the first step in mathematical induction?
Answer:
Show that the statement is true for n=1
Step-by-step explanation:
Hey,
Show that the statement is true for n=1
You can check my other answer there which explains a little bit more the ideas.
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thank you
Gina, Sam, and Robby all rented movies from the same video store. They each rented some dramas, comedies, and documentaries. Gina rented 11 movies total. Sam rented twice as many dramas, three times as many comedies, and twice as many documentaries as Gina. He rented 27 movies total. If Robby rented 19 movies total with the same number of dramas, twice as many comedies, and twice as many documentaries as Gina, how many movies of each type did Gina rent?
Hi there! :)
Answer:
Gina rented 3 dramas, 5 comedies, and 3 documentaries.
Step-by-step explanation:
To solve, we will need to set up a system of equations:
Let x = # of dramas, y = # of comedies, and z = # of documentaries:
Write equations to represent each person:
Gina:
x + y + z = 11
Sam:
2x + 3y + 2z = 27
Robby:
x + 2y + 2z = 19
Write the system:
x + y + z = 11
2x + 3y + 2z = 27
x + 2y + 2z = 19
Begin by subtracting the third equation from the second:
2x + 3y + 2z = 27
x + 2y + 2z = 19
-----------------------
x + y = 8
If x + y = 8, plug this into the first equation:
(8) + z = 11
z = 11 - 8
z = 3
We found the # of documentaries Gina rented, now we must solve for the other variables:
Subtract the top equation from the third. Substitute in the value of z we solved for:
x + 2y + 2(3) = 19
x + y + (3) = 11
-------------------------
y + 3 = 8
y = 5
Substitute in the values for y and z to solve for x:
x + 5 + 3 = 11
x + 8 = 11
x = 11 - 8
x = 3.
Therefore, Gina rented 3 dramas, 5 comedies, and 3 documentaries.
Answer:
B- x + y + z = 11
2x + 3y + 2z = 27
x + 2y + 2z = 19
Step-by-step explanation:
I took the quiz
Complete the table for the given rule.
Rule: y = 6x – 4
х. Y
1
3
10
Answer:
a y = 2
b.y = 14
c. y =56
Step-by-step explanation:
a .6 (1)- 4=2
y=2
b. 6 (3)- 4
=18-4
y=14
c. 6 (10) - 4
= 60 - 4 =56
The data set {3, 7, 5, 4, 1} consists of the lengths, in minutes, of a sample of speeches at an awards banquet. Use a formula to find the standard deviation of the sample, and label it with the correct variable.
Answer:
Standard deviation = 2.2360679774998
Step-by-step explanation:
We are asked to find the Standard deviation of a samples of speeches as an awards.
The formula for sample standard deviation is given as:
√[(x - μ)²/N - 1 ]
Step 1
We find the mean (μ)
The mean of the sample =>
= Sum of term/ Number of terms
= (3 + 7 + 5 + 4 + 1)/5
= 20/5
= 4
Step 2
Find the Standard deviation of the sample
√[(x - μ)²/N - 1 ]
N = number of samples or terms = 5
= √[(3 - 4) ² + (7 - 4)² + (5 - 4)² +(4 - 4)² +(1 - 4)²/ 4]
= √ (1 ² + 3² + -1² + 0² + -3²/4)
= √( 1 + 9 + 1 + 0 + 9/4)
= √20/5 - 1
= √5
= 2.2360679774998
The standard deviation of the sample = 2.2360679774998
If there are 25 students in a class - 11 are guys and 14 are girls what is the probability that one of the students on the class is a guy?
Answer:
0.44
Step-by-step explanation:
11/25 = 0.44 = 44%
Answer:
11/25
Step-by-step explanation:
since there are 25 students, there will be 25 choices, and the 25 will be the denominator
and there are 11 guys so there will be 11 choices of guys and the 11 will go on top
Take thus quote, and embed (introduce) it into a complete sentence: "TV plots
and characters tended to be simple" The author is Ostergaard.
Kristin is building a pattern using triangles. The table shows the number of triangles in the first 4 terms of the pattern.
Term Number (7)
1 2 3 4
Number of Triangles (t) 1 3 5 7
Which formula describes the number of triangles in the nth term of the pattern?
O A n=1+2
O B. n=1+3
Oc. n = 21-1
OD n = 2t + 3
Answer:
[tex]\bold{n =2t-1}[/tex]
Step-by-step explanation:
Given table is:
[tex]\begin{center}\begin{tabular}{ c c}Term Number (t) & Number of triangles (n) \\ 1 & 1 \\ 2 & 3 \\ 3 & 5 \\ 4 & 7 \\\end{tabular}\end{center}[/tex]
i.e. when term number, t = 1, number of triangles (n) = 1
when term number, t = 2, number of triangles (n) = 3
when term number, t = 3, number of triangles (n) = 5
when term number, t = 4, number of triangles (n) = 7
If we closely look at the pattern, number of triangles (n) in each row are 1 lesser than twice of term number (t).
i.e. for [tex]t=1, n = 2\times 1 -1=1[/tex]
[tex]t=2, n = 2\times 2 -1=3[/tex]
[tex]t=3, n = 2\times 3 -1=5[/tex]
[tex]t=4, n = 2\times 4 -1=7[/tex]
Therefore, the number of triangles in the nth term will be given as:
[tex]\bold{n =2t-1}[/tex]
Answer:
an = 2t -1
Step-by-step explanation:
We are adding 2 each time
1+2 =3
3+2 = 5
5+2 = 7
an is the nth term in the sequence and t is the number of triangle
an =1+ 2(t-1)
Distribute
an = 1 +2t -2
an = 2t -1
What is the rise over run for the slope -11/9
Answer: 11 down and 9 right
Step-by-step explanation:
Slope IS rise over run where the top number of the fraction (numerator) determines the vertical distance --> positive is up, negative is down
and the bottom number of the fraction (denominator) determines the horizontal distance --> positive is right, negative is left.
Given slope = -11/9
the numerator is -11 so the "rise" is DOWN 11 units
the denominator is 9 so the "run" is RIGHT 9 units
What does it mean when the resulting temperature is above 0 on the number line? What does it mean when a temperature is below 0?
Answer:
It means that above 0 degrees Celsius the water does not freeze, whereas 0 degrees are freezing teperatures of water.
Step-by-step explanation:
Water freezes at 0 degrees Celsius, but the freezing temperature can be lowered by adding salt to the water. A student discovered that adding half a cup of salt to a gallon of water lowers its freezing temperature by 7 degrees Celsius. What is the freezing temperature of the gallon of salt water?
0° - 7° = -7°
Among cases of heart pacemaker malfunctions, were found to be caused by firmware, which is software programmed into the device. If the firmware is tested in different pacemakers randomly selected from this batch of and the entire batch is accepted if there are no failures, what is the probability that the firmware in the entire batch will be accepted? Is this procedure likely to result in the entire batch being accepted?
Complete question is;
Among 8834 cases of heart pacemaker malfunctions, 504 were found to be caused by firmware, which is software programmed into the device. If the firmware is tested in three different pacemakers randomly selected from this batch of 8834 and the entire batch is accepted if there are no failures, what is the probability that the firmware in the entire batch will be accepted? Is this procedure likely to result in the entire batch being accepted?
Answer:
P(All three are not caused by firmware) = 83.84%
Probability that the entire batch will be accepted = 0.8384
Step-by-step explanation:
We are told that out of the 8834 cases of heart pacemaker malfunctions, 504 were found to be caused by firmware.
Thus,
Cases not caused by firmware = 8834 - 504 = 8330
So, probability of the first case not being affected by firmware is;
P(first case not caused by firmware) = 8330/8834
Also,
Probability of second case not being affected by firmware is given as;
P(second case not caused by firmware|first case not affected by firmware) = 8329/8833
Similarly,
Probability of third case not being affected by firmware is given as;
P(third case not caused by firmware|first and second not caused by firmware) = 8328/8832
Now, looking at the 3 Probabilities gotten, it is obvious that the events are not independent because the probability of occurence of one event depends on the probability of occurence of the other event.
Thus, we will make use of the general multiplication rule which is;
P(A & B) = P(B) × P(A|B)
Thus;
P(All three not caused by firmware) = P(first case not caused by firmware) × P(second case not caused by firmware|first case not affected by firmware) × P(third case not caused by firmware|first and second not caused by firmware)
Plugging in the relevant values, we have;
P(All three not caused by firmware) = (8330/8834) × (8329/8833) × (8328/8832)
P(All three are not caused by firmware) = 0.83840506679 ≈ 83.84%
Lila is camping with her family. She wants to hike to the lake, go fishing, and hike back before 6:05 P.M. It will take 1 hour and 10 minutes to hike to the lake and 1 hour and 50 minutes to hike back. Lila wants to fish for 3 hours and 10 minutes. What is the latest time Lila can start the hike to the lake?
Lila will need to start the hike at 11: 55 a.m. to be back at exactly 6: 05 p.m. or at 11: 54 a.m. to be before 6: 05 p.m (6: 04 p.m.)
Explanation:
To solve this question, the first step is to calculate how much time does hiking to the lake, go fishing, and go back takes in total. This can be calculated by adding the time of the three activities. This means 1 hour 10 minutes + 3 hours 10 minutes + 1 hour 50 minutes which is equal to 6 hours 10 minutes. The detailed process is shown below.
Add the hours: 1 + 3 + 1 = 5
Add the minutes: 10+50 +10 = 70
Also, because the total of minutes is above 60 (each hour has 60 minutes) it is necessary to subtract 60 minutes and add 1 hour.
5 hours + 1 hour and 70 minutes - 60 minutes = 6 hours and 10 minutes
Now, to solve the question subtract the time of the activities to the time Lila needs to complete all the activities.
6: 05 p.m. - 6 hours and 10 minutes = 11: 55 a.m
You can get this result by substracting first the hours and then the minutes
6: 05 p.m. - 6 hours = 12: 05 p.m.
12: 05 - 10 minutes = 11: 55 a.m.
According to this, Lila will need to start the hike at 11: 55 a.m. to be back at exactly 6: 05 p.m. or at 11: 54 a.m. to be before 6: 05 a.m because if she starts at 11: 54 a.m. she will be back at 6:04, which is a minute before 6:05 p.m.
what are the comparison symbols for 5/6 and 2/5, 4/10 and 7/8, and 3/12 and 1/4
Answer like this: Example
=
<
>
Answer:
5/6 > 2/44/10 < 7/83/12 = 1/4Step-by-step explanation:
The comparison will be the same if you subtract the right side and compare to zero:
a/b ?? c/d . . . . . . . using ?? for the unknown comparison symbol
a/b - c/d ?? 0 . . . . subtract the fraction on the right
(ad -bc)/bd ?? 0 . . . combine the two fractions
ad - bc ?? 0 . . . . . . multiply by bd to make the job easier
__
5/6 and 2/5
5(5) -6(2) = 25 -12 > 0 ⇒ 5/6 > 2/5
4/10 and 7/8
4(8) -10(7) = 48 - 70 < 0 ⇒ 4/10 < 7/8
3/12 and 1/4
3(4) -12(1) = 0 ⇒ 3/12 = 1/4
_____
Of course, you can use your calculator (or your memory) to change each of these to a decimal equivalent. The comparison should be easy at that point.
0.833 > 0.400
0.400 < 0.875
0.250 = 0.250
Can someone please help me ASAP:(
Answer:
3 =x
Step-by-step explanation:
(segment piece) x (segment piece) = (segment piece) x (segment piece)
3x(x+1) = 4x*x
Divide each side by x
3(x+1) = 4x
Distribute
3x+3 = 4x
Subtract 3x from each side
3x-3x +3 = 4x-3x
3 =x
NEED HELP ASAP PLEASE!! The graph of F(x), shown below, resembles the graph of G(x) = x2, but it has
been stretched and shifted. Which of the following could be the equation of
Fx)?
10
G(X) = x2
10
Fx) = ?
Answer:
D. F(x) = ( (1/5)x)^2 - 4
Step-by-step explanation:
The standard transformation with a stretch and a shift is
F(x) = f(x/b) + k
The red curve has a vertex at (0,-4), and cuts the x-axis at (10,0)
That means that before the vertical shift (of k=-4), the vertex was at (0,0), and the curves passes through (10,4).
Substituting in the equation
F(10) = (10/b)^2 -4 = 0
solve for b
(10/b)^2-4 = 0
(10/b)= sqrt(4) = 2
b = 10/2 = 5
Therefore the transformation equation is
F(x) = (x/5)^2-4
The answer is
F(x) = ( (1/5)x)^2 - 4
What is the simplified form of the following expression? 2 StartRoot 18 EndRoot + 3 StartRoot 2 EndRoot + StartRoot 162 EndRoot 6 StartRoot 2 EndRoot 18 StartRoot 2 EndRoot 30 StartRoot 2 EndRoot 36 StartRoot 2 EndRoot
Answer:
[tex]18\sqrt2[/tex]
Step-by-step explanation:
To simplify:
[tex]2 \sqrt{18}+ 3 \sqrt2+ \sqrt{162 }[/tex]
First of all, let us write 18 and 162 as product of prime factors:
[tex]18 = 2 \times \underline{3 \times 3}\\162 = 2 \times \underline{3 \times 3} \times \underline{3 \times 3}[/tex]
The pairs are underlined as above.
While taking roots, only one of the numbers from the pairs will be chosen.
Now, taking square roots.
[tex]\sqrt{18} =3 \sqrt2[/tex]
[tex]162 = 3 \times 3 \times \sqrt 2 = 9 \sqrt2[/tex]
So, the given expression becomes:
[tex]2 \sqrt{18}+ 3 \sqrt2+ \sqrt{162 } = 2 \times 3\sqrt2 + 3\sqrt2 +9\sqrt2\\\Rightarrow 6\sqrt2 + 3\sqrt2 +9\sqrt2\\\Rightarrow \sqrt2(6+3+9)\\\Rightarrow \bold{18\sqrt2}[/tex]
So, the answer is:
[tex]18\sqrt2[/tex] or 18 StartRoot 2 EndRoot
Answer:
its B. 18 sqrt(2)
Step-by-step explanation:
just took test
The value of y varies jointly with x and z. If y = 7 when z = 196 and x = 2, find the value of y when x = 3 and z = 336. I will rate you brainliest
Answer:
18
Step-by-step explanation:
Given that:
y∞ xz
y=kxz. Where k is constant
When z=196 and x= 2 then y= 7
7=(196)(2)k
7=392k
k=1/56
There fore y=(1/56)xz
When x=3 and z =336
y=(1/56)xz
y=(1/56)(336)(3)
y=18
if value of y varies jointly with x and z. If y = 7 when z = 196 and x = 2 then the value of y when x = 3 and z = 336 is 18.
What is Ratio?A ratio is an ordered pair of numbers a and b, written a / b where b does not equal 0.
Value of y varies jointly with x and z.
y ∞ xz
y=kxz.
Where k is constant
When z=196 and x= 2 then y= 7
Let us find the value of k
7=(196)(2)k
7=392k
Divide both sides by 7
k=1/56
y=(1/56)xz
When x=3 and z =336
y=(1/56)xz
y=(1/56)(336)(3)
y=18
Hence, the value of y when x = 3 and z = 336 is 18.
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A box is filled with 8 blue cards, 6 red cards, and 6 yellow cards. A card is chosen at a random from the box. What is the probability that the card is not red ? Write your answer as a fraction.
Answer:
14/20 or .7 or 70%
Step-by-step explanation:
Total Number of cards: 20
Number of Red cards: 6
The leftover cards: 20 -6 = 14
The probability of not getting a red = 14/20
14/20 as a decimal = 14/20 = 70/100 = .7
14/20 as a percent = 14/20 = 70/100 = 70%
George's height is 1.75 meters and Martha's height is 160 centimeters. How much taller is George than Martha in millimeters?
George should be 150 mm taller than Martha.
Calculation of the height in millimeters:
Since George's height is 1.75 meters and Martha's height is 160 centimeters.
So here we convert the meters to mm
So,
[tex]= 1.75\times 100\\\[/tex]
= 1750 mm
Now 160 cm to mm
So,
[tex]= 160\times 10[/tex]
= 1,600 mm
So, the difference should be
= 1,750 - 1,600
= 150 mm
Therefore, George should be 150 mm taller than Martha.
Learn more about height here: https://brainly.com/question/15810288
Tanθ - cosecθ secθ (1-2 cos²θ) = cotθ
Answer:
I thinksomething is wrong.
I'm getting another proving it's-tan thita.
I hope this is the one you are searching for..
A point (x,y) is a distance of 6 units from the x-axis. It is a distance of 5 units from the point (8,3). It is a distance [tex]\sqrt{n}[/tex] from the origin. Given that x<8, what is n?
Answer: n = 52
Step-by-step explanation:
when we have two vectors (x,y) and (a,b) the distance between the vectors is:
D = √( (x - a)^2 + (y - b)^2)
now, we know that:
1) the distance between (x, y ) and the x-axis is 6 units.
The nearest point to (x, y) in the x-axis is the point (x, 0) so we have:
D = 6 = √( (x - x)^2 + (y - 0)^2) = √y^2
so y can be 6 or -6.
So we know that y = 6, and now we can write our point as (x, +-6)
2) The distance between our point and (8, 3) is 5 units:
D = √( (x - 8)^2 + (y - 3)^2) = 5.
And we know that the distance from the origin, (n, n) is:
D = √n = √(x^2 + y^2}
n = x^2 + y^2
Now, we should start with:
√( (x - 8)^2 + (y - 3)^2) = 5
first suppose that y = -6, then:
√( (x - 8)^2 + (-6 - 3)^2) = √( (x - 8)^2 + (-9)^2) = 5.
√( (x - 8)^2 + 81) = 5.
Then we must have that:
and we know that √25 = 5
so (x-8)^2 + 81 = 25
this can never happen, so we can discard y = -6
Now the second case, if y = 6,
√( (x - 8)^2 + (6 - 3)^2) = 5.
√( (x - 8)^2 + (3)^2) = 5.
√( (x - 8)^2 + 9) = 5.
here:
(x - 8)^2 + 9 = 25
(x - 8)^2 = 16
(x - 8) = √16 = +-4
So again we have two cases:
if x - 8 = 4, then:
x = 4 + 8 = 12
but we must have x < 8, so this can be discarded.
now, if x - 8 = -4 then:
x = -4 + 8 = 4, this is an acceptable answer, then our point is (4, 6)
And we have:
n = 4^2 + 6^2 = 16 + 36 = 52
around 2.232 to the nearest hundredth
[tex]2.232\approx2.32[/tex]
An honest die is rolled. If the roll comes out even (2, 4, or 6), you will win $1; if the roll comes out odd (1,3, or 5), you will lose $1, Suppose that in one evening you play this game n=2500 times in a row.
(a) Estimate the probability that by the end of the evening you will not have lost any money.
(b) Estimate the probability that the number of "even rolls" (roll a 2, 4, or 6) will fall between 1250 and 1300.
(c) Estimate the probability that you will win $100 or more.
Answer:
(a) 50%
(b) 47.5%
(c) 2.5%
Step-by-step explanation:
According to the honest coin principle, if the random variable X denotes the number of heads in n tosses of an honest coin (n ≥ 30), then X has an approximately normal distribution with mean, [tex]\mu=\frac{n}{2}[/tex] and standard deviation, [tex]\sigma=\frac{\sqrt{n}}{2}[/tex].
Here the number of tosses is, n = 2500.
Since n is too large, i.e. n = 2500 > 30, the random variable X follows a normal distribution.
The mean and standard deviation are:
[tex]\mu=\frac{n}{2}=\frac{2500}{2}=1250\\\\\sigma=\frac{\sqrt{n}}{2}=\frac{\sqrt{2500}}{2}=25[/tex]
(a)
To not lose any money the even rolls has to be 1250 or more.
Since, μ = 1250 it implies that the 50th percentile is also 1250.
Thus, the probability that by the end of the evening you will not have lost any money is 50%.
(b)
If the number of "even rolls" is 1250, it implies that the percentile of 1250 is 50th.
Then for number of "even rolls" as 1300,
1300 = 1250 + 2 × 25
= μ + 2σ
Then P (μ + 2σ) for a normally distributed data is 0.975.
⇒ 1300 is at the 97.5th percentile.
Then the area between 1250 and 1300 is:
Area = 97.5% - 50%
= 47.5%
Thus, the probability that the number of "even rolls" will fall between 1250 and 1300 is 47.5%.
(c)
To win $100 or more the number of even rolls has to at least 1300.
From part (b) we now 1300 is the 97.5th percentile.
Then the probability that you will win $100 or more is:
P (Win $100 or more) = 100% - 97.5%
= 2.5%.
Thus, the probability that you will win $100 or more is 2.5%.
