If X ~ Exponential(µ), then the mean of X is 1/µ. So if the mean of X is twice the mean of Y, then the mean of Y is 1/(2µ), so that Y ~ Exponential(2µ).
We're given that
P(X > 50) = 1 - P(X ≤ 50) = 1 - Fx (50) ≈ 0.7788
==> Fx (50) = P(X ≤ 50) ≈ 0.2212
where Fx is the CDF of X, which is given for 0 ≤ x < ∞ to be
Fx (x) = 1 - exp(-µx)
Solve for µ :
1 - exp(-50µ) ≈ 0.2212 ==> µ ≈ -ln(0.7788)/50 ≈ 0.005
Then we have
P (Y > 40) = 1 - P (Y ≤ 40) = 1 - Fy (40)
where Fy is the CDF of Y,
Fy (y) = 1 - exp(-2µy)
so that
P (Y > 40) ≈ 1 - exp(-2 × 0.005 × 40) ≈ 0.3297
True or false? If it is false, replace the underlined word with the correct word. (Constant is underlined) The constant term in a polynomial expression is a number that is not multiplied by a
variable.
Answer:
true
Step-by-step explanation:
what else would it be. that is exactly the reason why we have constants.
n a history class there are 88 history majors and 88 non-history majors. 44 students are randomly selected to present a topic. What is the probability that at least 22 of the 44 students selected are non-history majors
Answer:
0.5675 = 56.75% probability that at least 22 of the 44 students selected are non-history majors.
Step-by-step explanation:
The students are chosen without replacement from the sample, which means that the hypergeometric distribution is used to solve this question. We are working also with a sample with more than 10 history majors and 10 non-history majors, which mean that the normal approximation can be used to solve this question.
Hypergeometric distribution:
The probability of x successes is given by the following formula:
[tex]P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}[/tex]
In which:
x is the number of successes.
N is the size of the population.
n is the size of the sample.
k is the total number of desired outcomes.
Combinations formula:
[tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.
[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Approximation:
We have to use the mean and the standard deviation of the hypergeometric distribution, that is:
[tex]\mu = \frac{nk}{N}[/tex]
[tex]\sigma = \sqrt{\frac{nk(N-k)(N-n)}{N^2(N-1)}}[/tex]
In this question:
88 + 88 = 176 students, which means that [tex]N = 176[/tex]
88 non-history majors, which means that [tex]k = 88[/tex]
44 students are selected, which means that [tex]n = 44[/tex]
Mean and standard deviation:
[tex]\mu = \frac{44*88}{176} = 22[/tex]
[tex]\sigma = \sqrt{\frac{44*88*(176-88)*(176-44)}{176^2(175-1)}} = 2.88[/tex]
What is the probability that at least 22 of the 44 students selected are non-history majors?
Using continuity correction, as the hypergeometric distribution is discrete and the normal is continuous, this is [tex]P(X \geq 22 - 0.5) = P(X \geq 21.5)[/tex], which is 1 subtracted by the p-value of Z when X = 21.5. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{21.5 - 22}{2.88}[/tex]
[tex]Z = -0.17[/tex]
[tex]Z = -0.17[/tex] has a p-value of 0.4325
1 - 0.4325 = 0.5675
0.5675 = 56.75% probability that at least 22 of the 44 students selected are non-history majors.
The sum of the lengths of any two sides of a triangle must be greater than the third side. If a triangle has one side that is 18 inches and a second side that is 3 inches less than twice the third side, what are the possible lengths for the second and third sides?
Answer: One side could be 18 and the other side will be 33.
Step-by-step explanation:
Side #1 = 18Side #2 = 2x - 3Side #3 = xOne way of setting up the inequality is: Side #2 + Side #3 > Side #1
[tex]2x-3+x>18\\3x-3>18\\3x>18+3\\3x>21\\x>7[/tex]
Another way of setting up the inequality is: Side #1 + Side #3 > Side #2
[tex]18+x>2x-3\\18+3>2x-x\\x<21[/tex]
Final way of setting up the inequality is: Side #1 + Side #2 > Side #3
[tex]18+2x-3>x\\15>x-2x\\15>-x\\x>-15[/tex]
Therefore, we have the range for our value of x, which is between 7 and 21. Any possible value between works. Negative measurements are rejected. One of the sides would equal the x-value, while the other side would equal the value of 2x-3.
What is the slope-intercept equation of the line below?
10 minutes left
Answer:
y=-3x+4
Step-by-step explanation:
The y intercept is 4 because the line crosses the y axis at the 4 tic mark
The slope will be -3 because the y decreases by 3 every time the x incerases by 1
y=mx+b
y=-3x+4
13 is subtracted from the product of 4 and a certain number. The result is equal to the sum of 5 and the original number. Find the number.
Answer:
The number is 6.
Step-by-step explanation:
[tex]4x-13=x+5\\3x-13=5\\3x=18\\x=6[/tex]
Can someone do #2?❤️
Answer:
b
Step-by-step explanation:
A proportional relationship is a straight line. Is must also go through the point (0,0)
b
Answer:
Step-by-step explanation:
A proportional relationship is a straight line. Is must also go through the point (0,0)
Find the missing side length. Leave your answers radical in simplest form. PLEASE HURRY
Answer:
y=8 and x=8 ✔3. the check is meant to be square root symbol lol
Please answer! These r my last questions
Answer:
8. -2a+14
9. w=3/2
Step-by-step explanation:
8.
The distributive property states that we can multiply each component in the parenthesis separately by the number on the outside, and then add that up to get our final answer.
For -2(a-7), this means that we can multiply -2 by a and then -2 by -7 (as 2 is the number on the outside, and a and -7 are the components in the parenthesis), add them up, and get our answer. This can be expressed as
-2 * a + (-2) * (-7) = final answer
= -2 * a + 14
We know that -2 * -7 = 14 because 2 * 7 = 14, and the two negatives in multiplication cancel each other out
9.
Using the subtraction property of equality, we can isolate the variable (w) and its coefficient (-2/3) by subtracting 5, resulting in
(-2/3)w = 4-5 = -1
Next, we can use the multiplication property of equality to isolate the w. To isolate the w, we can multiply its coefficient by its reciprocal. The reciprocal is the fraction flipped over. For (-2/3), its reciprocal is (-3/2), flipping the 2 and 3. We can multiply both sides by (-3/2) to get
w = (-3/2)
To check this, we can plug (-3/2) for w in our original equation, so
(-2/3) * (-3/2) + 5 = 4
-1 + 5 = 4
4 = 4
This works!
Which graph best represents the equation -4x + 5y = 8
Answer:
a or b
Step-by-step explanation:
the pictures are a little hard to tell apart but im my opinion go for a because its the closest
Answer:
A.)
Step-by-step explanation:
I took the test.
Which expression does NOT equal to 10
_
12
I believe your answer is D
Answer:
option(d)
Step-by-step explanation:
5/12 + 4/12 + 3/12 + 2/12 + 1/12
=> (5+4+3+2+1)/12
=> 15/12 ≠ 10/12
You can run at a speed of 4 mph and swim at a speed of 2 mph and are located on the shore, 6 miles east of an island that is 1 mile north of the shoreline. How far (in mi) should you run west to minimize the time needed to reach the island
9514 1404 393
Answer:
5.423 miles
Step-by-step explanation:
Let x represent the distance to run. Then the remaining distance to the point that is closest to the island is (6-x) miles. The straight-line distance (d) to the point x from the island is given by the Pythagorean theorem:
d² = 1² +(6 -x)² = x² -12x +37
d = √(x² -12x +37)
The total travel time is the sum of times running and swimming. Each time is found from ...
time = distance/speed
total time = x/4 + d/2 = x/4 +(1/2)√(x² -12x +37)
__
The total time will be minimized when its derivative with respect to x is zero.
t' = 1/4 +(1/4)(2x -12)/√(x² -12x +37) = 0
Multiplying by 4 and combining fractions, we can see the numerator will be ...
√(x² -12x +37) +2x -12 = 0
Subtracting the radical term and squaring both sides, we get ...
4x² -48x +144 = x² -12x +37
3x² -36x +107 = 0
The quadratic formula tells us the smaller of the two roots is ...
x = (36 -√(36² -4(3)(107)))/(2(3)) = (36 -√12)/6 ≈ 5.423 . . . mi
You should run 5.423 miles west to minimize the time needed to reach the island.
__
A graphing calculator solves this nicely. The attached graph shows the time is a minimum when you run 5.423 miles.
f(x) = 3x3
3.3 – 2.02 + 4x - 5
g(x) = 6x - 7
Find (f + g)(x).
Answer:
C) (f+g)(x)= 3x^3-2x^2+10x-12
Write this ratio as a fraction in simplest form without any units.
7 gallons to 40 quarts
9514 1404 393
Answer:
7/10
Step-by-step explanation:
In order to make the units cancel, they must be the same. There are 4 quarts in 1 gallon, so 40 quarts = 10×4 quarts = 10×(1 gal) = 10 gal.
Then the ratio is ...
(7 gal)/(10 gal) = 7/10
Bob travels from Inglewood to anytown; a distance of 20 km.
He walks 800 meters and cycles the rest of the way.
What percentage of the journey does he travel by bicycle?
Answer:
Total Distance = 20km = 20 × 1000 = 20,000 m
Distance walked = 800m
Distance travelled by cycle = 20,000 - 800 = 19,200m
Percentage of journey by cycle = (distance travelled by cycle ÷ total distance) × 100
Percentage of journey by cycle = (19200 / 20000) * 100
Percentage of journey by cycle = 96%
Rewrite the expression as the algebraic expression in x
Sin
(tan^-1(x))
9514 1404 393
Answer:
sin(tan^-1(x)) = x/√(x² +1)
Step-by-step explanation:
We know that for an angle in a right triangle...
Tan = Opposite/Adjacent
and
Sin = Opposite/Hypotenuse
so we can let Opposite = x and Adjacent = 1. The Pythagorean theorem tells us that ...
Hypotenuse² = Opposite² + Adjacent² = x² +1
Then the sine of the angle is ...
sin(tan^-1(x)) = x/√(x² +1)
Three brothers enter a race with 8 friends. The racers draw lots to determine their
starting positions. What is the probability that the older brother, Mike, will start in lane 1, with
his other brothers, Stan and Steve beside him in lanes 2 and 3 in that order?
what is the main protein of a scientific investigation A. To form an opinion B. to test a hypothesis C. To persuade a bias D. To teach a lesson
Answer:
D.To teach a lesson
Step-by-step explanation:
Hope it helps you
PLEASE HELP FAST!! WILL GIVE FIRST PERSON THAT RESPONDS A HIGH RATING AND POINTS!
Answer:
Step-by-step explanation:
3
What are the factors of 60 ???
Answer:
Factors are 1,2,3,4,5,6,10,12,15,20,30,60
Step-by-step explanation:
Hope this helps
Factors refers to those numbers which muntiplied that no.here, numbers that muntiply 60 are 1,2,3,4,5,6,10,12,15,20,30,60.
thus these numbers are factors of 60.
Anna earned $9 an hour babysitting. She wants
to buy a 16 GB iPod that is $120. Anna has
saved $45 so far. How many more hours of
babysitting does she need to do to earn the rest
to purchase the iPod
Answer:
8.33 hours
Step-by-step explanation:
120-45 = 75
75 ÷ 9 = 8.33
Gabrielle's age is two times Mikhail's age. The sum of their ages is 30 . What is Mikhail's age?
Step-by-step explanation:
G=2m
m+G=30
m +2m =30
3m=30
m=10
Which expression is equivalent to:
15x + 20y
5(4x+3y)
5(3x+4y)
5y(3x + 4)
Answer:
5(3x+4y)
Step-by-step explanation:
If the triangle above is translated two units to the right, what is the correct coordinate for A'?
Answer: 0, 5
Step-by-step explanation: a translation is just like sliding the object in this case a triangle/point on the triangle. so the point it is at now is -2, 5 because it is 2 to the left and 5 up. and if you go to the right 2. then you are adding 2 to the x value. so -2 +2 = 0. which is how you get 0, 5
In how many ways can a committee of 3 men and 2 women can be formed from 7 men and 5 women?
Answer:
in five (5) ways a committee can be formed from 7 men and 5 women
This figure shows △ABC. BD¯¯¯¯¯ is the angle bisector of ∠ABC.
What is AD?
Answer:
AD = 8/3 units
Step-by-step explanation:
Based on the angle bisector theorem, angle bisector BD divides AC into AD and CD such that they are proportional to AB and CB.
This implies:
AB/AD = CB/CD
AB = 8
CB = 10
Set AD equal to x
AD = x
CD = 6 - x
Substitute the values
8/x = 10/(6 - x)
8(6 - x) = 10(x)
48 - 8x = 10x
48 - 8x + 8x = 10x + 8x
48 = 18x
48/18 = 18x/18
8/3 = x
x = 8/3
AD = 8/3 units
Answer:8/3
Step-by-step explanation:
I just took the quiz
what equation shows a slope of 2/3 and a white intercept of 0, -2
y = 2/3 x - 2
Or
y + 2 = 2/3 ( x )
Answer:
y= 2/3x - 2
hope this helps :)
Devaughn is 6 years older than Sydney. The sum of their ages is 56 . What is Sydney's age?
Answer:
Devaughn = 31, Sydney = 25
Step-by-step explanation:
(56-6)÷2= 25
So they would both be 25 if they were the same age but Devaughn is 6 years older so 25+6=31
ATQ
[tex]\\ \sf\longmapsto x+x+6=56[/tex]
[tex]\\ \sf\longmapsto 2x+6=56[/tex]
[tex]\\ \sf\longmapsto 2x=56-6[/tex]
[tex]\\ \sf\longmapsto 2x=50[/tex]
[tex]\\ \sf\longmapsto x=\dfrac{50}{2}[/tex]
[tex]\\ \sf\longmapsto x=25[/tex]
The number formed by subtracted 1 from smallest 7-digit number is
Step-by-step explanation:
the number formed by subtracting 1 from the smallest 7 digit number is largest 6 digit number.
A certificate of deposit offers a nominal interest rate of 2.5 percent annually.
If inflation is 1 percent, what is the real rate of return?
To solve this question, the real rate of return formula is used, and we apply the data given in the exercise into the formula to find the real rate of return.
Formula for the real rate of return:
[tex]R = \frac{1 + N}{1 + i} - 1[/tex]
In which N is the nomial rate and i is the inflation rate, as decimals.
A certificate of deposit offers a nominal interest rate of 2.5 percent annually.
This means that [tex]N = 0.025[/tex]
Inflation is 1 percent
This means that [tex]i = 0.01[/tex]
What is the real rate of return:
Now we apply the formula:
[tex]R = \frac{1 + 0.025}{1 + 0.01} - 1[/tex]
[tex]R = 1.0149 - 1[/tex]
[tex]R = 0.0149[/tex]
0.0149*100% = 1.49%
Thus, the real rate of return is of 1.49%.
For another example of a similar problem, you can check https://brainly.com/question/20164190
find the LCM of 210, 280, 360 by prime factorisation
Answer:
Step-by-step explanation:
210=2x3x5x7
280=2x2x2x5x7
360=2x2x2x3x3x5
Answer:
210= 2×3×5×7
280=2×2×2×5×7
360=2×2×2×3×3×5
common factors=2×2×2×3×5×7=840
uncommon factors=3
L.C.M=Common factors× uncommon factors
L.C.M=840×3
L.C.M=2520
Step-by-step explanation:
i hope it will be helpful
plzz mark as brainliest
