Answer:
Correct option is
C
10
5
10P
5
Total ways in which one passenger can stop =10
Total ways in which 5 passengers can stop =10∗10∗10∗10∗10
=10
5
We will select 5 floors from 10 floors and assign each individual to each floor to keep everyone isolated from each other
No. of ways in which no two persons stop at the same floor =10C
5
∗5!
=10P
5
⇒P(E)=10P
5
/10
5
A radioactive substance decays exponentially: The mass at time t is m(t) = m(0)e^kt, where m(0) is the initial mass and k is a negative constant. The mean life M of an atom in the substance is
[infinity]
M = âk â« te^kt dt.
0
For the radioactive carbon isotope, 14C, used in radiocarbon dating, the value of k is -0.000121. Find the mean life of a 14C atom.
Answer:
mean life = 8264.5 s
Step-by-step explanation:
k = - 0.000121
The relation is given by
[tex]m = mo e^{kt}[/tex]
Now, the mean life is the life time for which the sample retains.
The mean life is the reciprocal of the decay constant.
The relation between the mean life and the decay constant is
[tex]\tau =\frac{1}{k}\\\\\tau = \frac{1}{0.000121} = 8264.5 seconds[/tex]
The thickness X of aluminum sheets is distributed according to the probability density function f(x) = 450 (x2 - x) if 6 < x < 12 0 otherwise 5-1 Derive the cumulative distribution function F(x) for 6 < x < 12. The answer is a function of x and is NOT 1! Show the antiderivative in your solution. 5-2 What is E(X) = {the mean of all sheet thicknesses)? Show the antiderivative in your solution.
Solution :
Given :
[tex]f(x) = \left\{\begin{matrix}\frac{1}{450}(x^2-x) & \text{if } 6 < x < 12 \\ 0 & \text{otherwise}\end{matrix}\right.[/tex]
1. Cumulative distribution function
[tex]$P(X \leq x) = \int_{- \infty}^x f(x) \ dx$[/tex]
[tex]$=\int_{- \infty}^6 f(x) dx + \int_{6}^x f(x) dx $[/tex]
[tex]$=0+\int_6^x \frac{1}{450}(x^2-x) \ dx$[/tex]
[tex]$=\frac{1}{450} \int_6^x (x^2-x) \ dx$[/tex]
[tex]$=\frac{1}{450}\left[\frac{x^3}{3}-\frac{x^2}{2}\right]_6^x$[/tex]
[tex]$=\frac{1}{450}\left[ \left( \frac{x^3}{3} - \frac{x^2}{2}\left) - \left( \frac{6^3}{3} - \frac{6^2}{2} \right) \right] $[/tex]
[tex]$=\frac{1}{450}\left[\frac{x^3}{3} - \frac{x^2}{2} - 54 \right]$[/tex]
2. Mean [tex]$E(x) = \int_{- \infty}^{\infty} \ x \ f(x) \ dx$[/tex]
[tex]$=\int_{6}^{12}x . \left( \frac{1}{450} \ (x^2-x)\right)\ dx$[/tex]
[tex]$=\frac{1}{450} \int_6^{12} \ (x^3 - x^2) \ dx$[/tex]
[tex]$=\frac{1}{450} \left[\frac{x^4}{4} - \frac{x^3}{3} \right]_6^{12} \ dx$[/tex]
[tex]$=\frac{1}{450} \left[ \left(\frac{(12)^4}{4} - \frac{(12)^3}{3} \right) - \left(\frac{(6)^4}{4} - \frac{(6)^3}{3} \right) $[/tex]
[tex]$=\frac{1}{450} [4608 - 252]$[/tex]
= 17.2857
Which of the following is equivalent to the expression log2a=r? 2a = r logr2 = a 2r = a log2r = a
9514 1404 393
Answer:
(c) 2^r = a
Step-by-step explanation:
The relationship between log forms and exponential forms is ...
[tex]\log_2(a)=r\ \Leftrightarrow\ 2^r=a[/tex]
__
Additional comment
I find this easier to remember if I think of a logarithm as being an exponent.
Here, the log is r, so that is the exponent of the base, 2.
This equivalence can also help you remember that the rules of logarithms are very similar to the rules of exponents.
Answer: Choice C) [tex]2^r = a[/tex]
This is the same as writing 2^r = a
==========================================================
Explanation:
Assuming that '2' is the base of the log, then we'd go from [tex]\log_2(a) = r[/tex] to [tex]2^r = a[/tex]
In either equation, the 2 is a base of some kind. It's the base of the log and it's the base of the exponent.
The purpose of logs is to invert exponential operations and help isolate the exponent. A useful phrase to help remember this may be: "if the exponent is in the trees, then we need to log it down".
The general rule is that [tex]\log_b(y) = x[/tex] converts to [tex]y = b^x[/tex] and vice versa.
1. Suppose half of all newborns are girls and half are boys. Hospital A, a large city hospital, records an average of 50 births a day. Hospital B, a small, rural hospital, records an average of 10 births a day. On a particular day, which hospital is less likely to record 80% or more female births?
Answer:
5%
Step-by-step explanation:
Hospital A (with 50 births a day), because the more births you see, the closer the proportions will be to 0.5.
Hospital B (with 10 births a day), because with fewer births there will be less variability.
The two hospitals are equally likely to record such an event, because the probability of a boy does not depend on the number of births
Two hospitals have an equal chance of recording such an event.
What is probability?The area of mathematics known as probability deals with numerical representations of the likelihood that an event will occur or that a statement is true. An event's probability is a number between 0 and 1, where, roughly speaking, 0 denotes the event's impossibility and 1 denotes certainty.
Given
Hospital A (with 50 births per day), as the proportions will be closer to 0.5 the more births you see.
Hospital B (with 10 births per day), thus there will be less unpredictability with fewer births.
Due to the fact that the likelihood of a boy does not rely on the number of births, the two hospitals have an equal chance of recording such an event.
To learn more about probability refer to:
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A point is selected at random from a line segment of length l, dividing it into two line segments. What is the probability that the longer line segment is at least three times as long as the shorter segment
Answer:
3/4
Step-by-step explanation:
Let a be the length of the shorter line segment and b be the length of the longer line segment.
Since the length of the line segment is l, we have that the length of the line segment equals length of shorter line segment + length of longer line segment.
So, l = a + b
Since we require that the longer line segment be at least three times longer than the shorter line segment, we have that b = 3a
So, l = a + b
l = a + 3a
l = 4a
The probability that the shorter line segment will be a(or 3 times shorter than b) is P(a) = length of shorter line segment/length of line segment = a/l
Since l = 4a.
a/l = 1/4
So, P(a) = 1/4
The probability that a will be less than 3 times shorter that b is P(a ≤ 1) = P(0) + P(a) = 0 + 1/4 = 1/4
The probability that b will be 3 times or more greater than a is thus P(b ≥ 3) = 1 - P(a ≤ 1) = 1 - 1/4 = 3/4
A loan of £1000 has a compound interest rate of 2.7% charged monthly. Express the original loan as a percentage of the total amount awed after 2 months if no payment are made
Answer:
£1054.729
Step-by-step explanation:
To find compound interest you need to use the equation 1000(1.027)^x.
To find the interest rate (1.027):
100 + 2.7 = 102.7
102.7 / 100 = 1.027
The value of x is the amount of months if no payment is made in this situation, so 2 would be the x value for this problem.
Hope this helps!
PLEASE HELPPPP WILL GIVE BRAINLIESTTTT
Factor the following expressions completely. Show and check all work on your own paper.
9x2-18x+9
Hi there!
[tex]\large\boxed{9(x - 1)^{2}}[/tex]
9x² - 18x + 9
We can begin by factoring out a 9 from each term:
9(x² - 2x + 1)
Now, find two terms that add up to -2 and equal 1 when multiplied. We get:
9(x - 1)(x - 1)
Or:
9(x - 1)²
The ocean surface is at 0 ft elevation. A diver is underwater at a depth of 138 ft. In this area, the ocean floor has a depth of 247 ft. A rock formation rises to a peak 171 ft above the ocean floor. How many feet below the top of the rock formation is the diver?
Answer:
The ocean surface is at 0 ft elevation. A diver is underwater at a depth of 138 ft. In this area, the ocean floor has a depth of 247 ft.
Step-by-step explanation:
A bricklayer needs to order 6 300 kg of building sand.
a) Write 6 300 kg in grams, giving your answer in standard form.
One grain of this sand approximately weighs 7 x 10°g.
b) How many grains of sand are there in 6 300 kg of sand? Give your answer in standard from.
Answer:
It would be 6300000. I can't write this in standard form.
Step-by-step explanation:
Answer:
6.3 x 10^6
Step-by-step explanation:
Find the perimeter of the
polygon if ZB = D.
3 om
B
4 cm
D
5 cm
C
P = [?] cm
Answer:
16 cm
Step-by-step explanation:
4 + 4 + 3 + 5 = 16
The = sign means that B (which is 4 cm) is equal to D (which had no number)
And because it says that B = D (with the squiggly line (or a tilde)) And the L's (which means that the letters represent an angle) All you have to do is add the numbers together, and you get 16.
Sorry if I explained it badly, you at least got the answer.
(And also, if I'm wrong, please tell me.)
Answer:
P = 32 cm
Step-by-step explanation:
Im just putting the right answer up so you don't accidentally put in the wrong one.
You and a friend were invited to a
party. You both were asked to bring
pizzas and chips. Your friend brought
three pizzas and four bags of chips
and spent $48.05. You brought five
pizzas and two bags of chips and
spent $67.25. What is the cost of
each? Answer should be in (Pizza, Chips)
Answer:
Pizza = 12.35
Chips = 2.75
Step-by-step explanation:
Let :
Pizza = x
chips = y
3x + 4y = 48.05 - - - (1)
5x + 2y = 67.25 - - - (2)
Multiply (1) by 5 and (2) by 3
15x + 20y = 240.25
15x + 6y = 201.75
Subtract :
20y - 6y = 240.25 - 201.75
14y = 38.50
y = 38.50/ 14
y = 2.75
Put y = 2.75 in (1)
3x + 4(2.75) = 48.05
3x + 11 = 48.05
3x = 48.05 - 11
3x = 37.05
x = 37.05 / 3
x = 12.35
Pizza = 12.35
Chips = 2.75
a + b·c = a + c·b is an example of the associative property.
Answer:
yes , This is an example of the associative property.
Step-by-step explanation:
I will mark you brainliest if you provide evidence you know what your doing
Work out the problem and make the answer clear
Option C
SOLUTION:
We need to find the value of B - CF
First find the value CF:
[tex]CF=\left[\begin{array}{ccc}12&0&1.5\\1&-6&7\\\end{array}\right] \left[\begin{array}{ccc}-2&0\\0&8\\2&1\end{array}\right][/tex]
[tex]CF=\left[\begin{array}{ccc}12(-2)+0 *0+1.5*2&12*0+0.8+1.5*1\\1*(-2)+(-6)*0+7.2&1*0+(-6)*8+7.1\\\end{array}\right][/tex]
[tex]CF=\left[\begin{array}{ccc}-21&1.5\\12&-41\\\end{array}\right][/tex]
Now find value of B - CF:
[tex]B-CF=\left[\begin{array}{ccc}2&8\\6&3\\\end{array}\right] -\left[\begin{array}{ccc}-21&1.5\\12&-41\\\end{array}\right][/tex]
[tex]B-CF=\left[\begin{array}{ccc}23&6.5\\-6&44\\\end{array}\right][/tex]
∴ the value of B - CF is [tex]\left[\begin{array}{ccc}23&6.5\\-6&44\\\end{array}\right][/tex]
I hope this helps....
Yess again pls help!
Tyyy
Two balls are drawn with replacement from a bag containing 12 red,3 white and 1 blue balls.what is the probability that both are red?
The probability that both the balls are red = [tex]\bold{\frac{11}{20}}[/tex]
What is probability?"Probability is a branch of mathematics which deals with finding out the likelihood of the occurrence of an event."
Formula of the probability of an event A is:P(A) = n(A)/n(S)
where, n(A) is the number of favorable outcomes, n(S) is the total number of events in the sample space.
What is the formula of combination?"[tex]^nC_r=\frac{n!}{r!(n-r)!}[/tex]"
For given question,
a bag contains 12 red, 3 white and 1 blue balls.
Total balls = 12 + 3 + 1
Total = 16
Two balls are drawn from a bag.
The number of possible ways of drawing 2 balls from the bag are:
Using combination formula,
[tex]^{16}C_2\\\\=\frac{16!}{2!(16-2)!}\\\\ =\frac{16!}{2!\times 12!}\\\\ =120[/tex]
So, n(S) = 120
Two balls are drawn with replacement from a bag.
We need to find the probability that both are red.
Let event A: both the balls are red
[tex]\Rightarrow n(A)=^{12}C_2[/tex]
Using combination formula,
[tex]^{12}C_2\\\\=\frac{12!}{2!\times (12-2)!}\\\\= \frac{12!}{2!\times 10!}\\\\ =66[/tex]
Using probability formula,
[tex]\Rightarrow P(A)=\frac{n(A)}{n(S)}\\\\\Rightarrow P(A)=\frac{66}{120}\\\\\Rightarrow P(A)=\frac{11}{20}[/tex]
Therefore, the probability that both the balls are red = [tex]\bold{\frac{11}{20}}[/tex]
Learn more about probability here:
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I need help solving this problem .
Step-by-step explanation:
here is the answer to your question
1. You measure 24 textbooks' weights, and find they have a mean weight of 75 ounces. Assume the population standard deviation is 3.3 ounces. Based on this, construct a 90% confidence interval for the true population mean textbook weight.
2. You measure 37 backpacks' weights, and find they have a mean weight of 45 ounces. Assume the population standard deviation is 10.1 ounces. Based on this, construct a 95% confidence interval for the true population mean backpack weight.
3. You measure 30 watermelons' weights, and find they have a mean weight of 37 ounces. Assume the population standard deviation is 4.1 ounces. Based on this, what is the maximal margin of error associated with a 90% confidence interval for the true population mean watermelon weight.
4. A student was asked to find a 99% confidence interval for widget width using data from a random sample of size n = 16. Which of the following is a correct interpretation of the interval 11.8 < μ < 20.4?
A. There is a 99% chance that the mean of a sample of 16 widgets will be between 11.8 and 20.4.
B. The mean width of all widgets is between 11.8 and 20.4, 99% of the time. We know this is true because the mean of our sample is between 11.8 and 20.4.
C. With 99% confidence, the mean width of all widgets is between 11.8 and 20.4.
D. With 99% confidence, the mean width of a randomly selected widget will be between 11.8 and 20.4.
E. There is a 99% chance that the mean of the population is between 11.8 and 20.4.
5. For a confidence level of 90% with a sample size of 23, find the critical t value.
Answer:
(73.845 ; 76.155) ;
(41.633 ; 48.367) ;
1.273 ;
C. With 99% confidence, the mean width of all widgets is between 11.8 and 20.4. ;
1.717
Step-by-step explanation:
1.)
Given :
Mean, xbar = 75
Sample size, n = 24
Sample standard deviation, s = 3.3
α = 90%
Confidence interval = mean ± margin of error
Margin of Error = Tcritical * s/√n
Tcritical at 90% ; df = 24 - 1 = 23
Tcritical = 1.714
Margin of Error = 1.714 * 3.3/√24 = 1.155
Confidence interval = 75 ± 1.155
Confidence interval = (73.845 ; 76.155)
2.)
Given :
Mean, xbar = 45
Sample size, n = 37
Sample standard deviation, s = 10.1
α = 95%
Confidence interval = mean ± margin of error
Margin of Error = Tcritical * s/√n
Tcritical at 95% ; df = 37 - 1 = 36
Tcritical = 2.028
Margin of Error = 2.028 * 10.1/√37 = 3.367
Confidence interval = 45 ± 3.367
Confidence interval = (41.633 ; 48.367)
3.)
Given :
Mean, xbar = 37
Sample size, n = 30
Sample standard deviation, s = 4.1
α = 90%
Margin of Error = Tcritical * s/√n
Tcritical at 90% ; df = 30 - 1 = 29
Tcritical = 1.700
Margin of Error = 1.700 * 4.1/√30 = 1.273
5.)
Sample size, n = 23
Confidence level, = 90%
df = n - 1 ; 23 - 1 = 22
Tcritical(0.05, 22) = 1.717
Would you kindly help me.Im having a hard time understanding and I've been crying a lot trying to understand it
A multiple regression model is ^Y = 8.114 + 2.005X1 + 0.774X2. Which of the following values is the estimate for the intercept parameter?
a. 0.774.
b. 8.114.
c. 1.000.
d. 2.005.
Answer:
B. 8.114
Step-by-step explanation:
The intercept parameter is the zero-grade component of the multilinear equation, that is, the component independent from [tex]x_{1}[/tex] and [tex]x_{2}[/tex]. Hence, the intercept parameter of the multilinear regression is 8.114. (Correct answer: B)
(-3).(+9)-(-24)-(+6).(+2)
Which division problem does the diagram below best illustrate?
A diagram with 8 ovals containing 4 squares each.
O 16 divided by 4 = 4
O 32 divided by 4 = 8
O 36 divided by 4 = 9
O 8 divided by 2 = 4
Answer:
The answer is 32 divided by 4
Step-by-step explanation:
Because in each box there is 4. There are 8 ovals all together. So 8×4, you get 32 and divide it by the number of squares in an oval which is 4
Answer:
the answer is 32 divided by 4=8
Step-by-step explanation:
because when you look at the ovals there's eight ovals and in side there's four squares..
HOPE THIS HELPS!!!!!
help i’ll give brainliest
Answer:
c c c c c c c c c c c c c c c c c c c c
Write an equation that expresses the following relationship.
d varies directly with w and inversely with p.
In your equation, use k as the constant of proportionality.
9514 1404 393
Answer:
d = kw/p
Step-by-step explanation:
When d varies directly with w, the equation is ...
d = kw
When d varies inversely with p, the equation is ...
d = k/p
When d does both, the equation is ...
d = kw/p
2. About 40 millions of aluminum cans can be recycled each month in the US. A quarter of these aluminum cans are used to make one aluminum boat. How many aluminum boats can be made in one year in the US?
Answer:
48
Step-by-step explanation:
About 40 millions of aluminum cans can be recycled each month in the US. A quarter of these aluminum cans are used to make one aluminum boat. How many aluminum boats can be made in one year in the US?
Given that:
Approximate Number of cans that can be recycled per month in the US = 40 million
Fraction of recycled cans that can be used to make an aluminum boat = 1/4
The number of aluminum boats that can be made in the US in one year :
If about 40 million cans are recycle per month :
The number of boat that can be made from each monthly recycled aluminum cans will be :
Number of monthly recycled can needed to make one boat:
1/4 * 40 million = 10 million cans
Hence, 40,000,000 / 10,000,000 = 4
4 aluminum boats can be made in one month :
Number of months in a year = 12
Number of aluminum boats that can be made in a year :
4 per month * 12 = 48 aluminum boats
What are the solutions to the system of equations graphed below?
Answer:
D
Step-by-step explanation:
solution is the points where the two graphs intersect.
they intersect at (-3,-3) and (0,6)
Evaluate the given expression for x=7.
8x +9
The answer is ---
Answer:
The answer is 65
Step-by-step explanation:
Evaluate:
8x + 9
When x = 7
Use PEMDAS order of operations:
8x + 9
= 8(7) + 9
= 56 + 9
= 65
Hope this helps
What is the equation of a parabola with its vertex at the origin and its focus at (–2, 0)?
Step-by-step explanation:
this is the answerI hope it helps
The graph of y=x^3 is transformed as shown in the graph below. Which equation represents the transformed function?
y = x cubed minus 4
y = (x minus 4) cubed
y = (negative x minus 4) cubed
y = (negative x) cubed minus 4
Answer:
y = (-x)^3 - 4
Step-by-step explanation:
Ok, for the function:
y = x^3
When x = 0, we have:
y = 0^3 = 0
So the original graph passes through the point (0, 0)
If we look at the given graph, we can see that the y-intercept (the value of y when x = 0) is:
y = -4
So, this is the graph of y = x^3 moved down 4 units.
You can also see that the graph goes downward as x increases (and up as x decreases) while for the function:
y = x^3
as x increases, we should see that y also increases.
Then we have a reflection across the x-axis.
Ok, now let's describe a vertical shift.
For a general function f(x), a vertical shift of N units is written as:
g(x) = f(x) + N
if N is positive, the shift is upwards
if N is negative, the shift is downwards.
And for a function f(x), a reflection across the x-axis is written as:
g(x) = - f(x)
Here we first apply the reflection across the x-axis, so we get:
g(x) = -f(x)
now we apply the shift 4 units downwards
g(x) = - f(x) - 4
replacing f(x) by our function, x^3
we get:
g(x) = -x^3 - 4
And because of the odd power, we can write:
-x^3 = (-x)^3
Then the function is:
g(x) = (-x)^3 - 4
The correct option is the last one.
y = (-x)^3 - 4
Levi makes the minimum salary for actuary. Andres maybe the median salary for cpa. Who makes more money
Answer:
Andres
why?
Because he is median salary for cpa
Cole biked at 5 mph for 1 hours. Which of the following choices show how far he biked?
A=5.5 miles
B=6.5 miles
C=7.5 miles
D=10 miles
Answer:
Most Likely A, 5.5 Miles
Step-by-step explanation:
However the question doesn't make sense as the logical answer is simply 5 miles, but the safest choice is 5.5
