Answer:
Step-by-step explanation:
This is a differential equation problem most easily solved with an exponential decay equation of the form
[tex]y=Ce^{kt}[/tex]. We know that the initial amount of salt in the tank is 28 pounds, so
C = 28. Now we just need to find k.
The concentration of salt changes as the pure water flows in and the salt water flows out. So the change in concentration, where y is the concentration of salt in the tank, is [tex]\frac{dy}{dt}[/tex]. Thus, the change in the concentration of salt is found in
[tex]\frac{dy}{dt}=[/tex] inflow of salt - outflow of salt
Pure water, what is flowing into the tank, has no salt in it at all; and since we don't know how much salt is leaving (our unknown, basically), the outflow at 3 gal/min is 3 times the amount of salt leaving out of the 400 gallons of salt water at time t:
[tex]3(\frac{y}{400})[/tex]
Therefore,
[tex]\frac{dy}{dt}=0-3(\frac{y}{400})[/tex] or just
[tex]\frac{dy}{dt}=-\frac{3y}{400}[/tex] and in terms of time,
[tex]-\frac{3t}{400}[/tex]
Thus, our equation is
[tex]y=28e^{-\frac{3t}{400}[/tex] and filling in 16 for the number of minutes in t:
y = 24.834 pounds of salt
Find the third term of a geometric progression if the sum of the first three terms is equal to 12, and the sum of the first six terms is equal to (−84).
Given:
The sum of the first three terms = 12
The sum of the first six terms = (−84).
To find:
The third term of a geometric progression.
Solution:
The sum of first n term of a geometric progression is:
[tex]S_n=\dfrac{a(r^n-1)}{r-1}[/tex]
Where, a is the first term and r is the common ratio.
The sum of the first three terms is equal to 12, and the sum of the first six terms is equal to (−84).
[tex]\dfrac{a(r^3-1)}{r-1}=12[/tex] ...(i)
[tex]\dfrac{a(r^6-1)}{r-1}=-84[/tex] ...(ii)
Divide (ii) by (i), we get
[tex]\dfrac{r^6-1}{r^3-1}=\dfrac{-84}{12}[/tex]
[tex]\dfrac{(r^3-1)(r^3+1)}{r^3-1}=-7[/tex]
[tex]r^3+1=-7[/tex]
[tex]r^3=-7-1[/tex]
[tex]r^3=-8[/tex]
Taking cube root on both sides, we get
[tex]r=-2[/tex]
Putting [tex]r=-2[/tex] in (i), we get
[tex]\dfrac{a((-2)^3-1)}{(-2)-1}=12[/tex]
[tex]\dfrac{a(-8-1)}{-3}=12[/tex]
[tex]\dfrac{-9a}{-3}=12[/tex]
[tex]3a=12[/tex]
Divide both sides by 3.
[tex]a=4[/tex]
The nth term of a geometric progression is:
[tex]a_n=ar^{n-1}[/tex]
Where, a is the first term and r is the common ratio.
Putting [tex]n=3,a=4,r=-2[/tex] in the above formula, we get
[tex]a_3=4(-2)^{3-1}[/tex]
[tex]a_3=4(-2)^{2}[/tex]
[tex]a_3=4(4)[/tex]
[tex]a_3=16[/tex]
Therefore, the third term of the geometric progression is 16.
A regression analysis between sales (in $1000s) and price (in dollars) resulted in the following equation: ŷ = 50,000 − 8x The above equation implies that an increase of _____. a. $8 in price is associated with an increase of $8,000 in sales b. $1 in price is associated with a decrease of $8,000 in sales c. $1 in price is associated with a decrease of $42,000 in sales d. $1 in price is associated with a decrease of $8 in sales
Answer:
b. $1 in price is associated with a decrease of $8,000 in sales
Step-by-step explanation:
Linear function:
A linear function has the following format:
[tex]y = mx + b[/tex]
In which m is the slope, which represents by how much y changes when x changes by 1.
ŷ = 50,000 − 8x
This means that [tex]m = -8[/tex], in thousands of dollars, so when the price x increases by 1, the sales will be decrease by $8,000, and thus, the correct answer is given by option b.
The equation implies that an increase (b) $1 in price is associated with a decrease of $8,000 in sales
The regression equation is given as:
[tex]\^y= 50000 - 8\^x[/tex]
A linear regression equation is represented as:
[tex]\^y= b_o+ b_1\^x[/tex]
Where:
b1 represents the slope or the unit rate of the equation
By comparison:
[tex]b_1 =-8[/tex]
Because the value of b1 is negative;
Then it means that, the unit rate represents a decrement
Hence, the equation implies that (b) $1 in price is associated with a decrease of $8,000 in sales
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A guide wire of length 108 meters runs from the top of an antenna to the ground. If the angle of elevation to the top of the antenna is 42.3 degrees, then what is the height of the antenna
Answer: Approximately 72.69 meters
Step-by-step explanation:
Antenna height = h[tex]sin(42.3)=\frac{opposite}{hypotenuse} =\frac{h}{108} \\\\108*sin(42.3)=h\\\\h=72.685[/tex]
The height of the antenna by using the Pythagoras theorem is 72.68 meters.
What is trigonometry?"Trigonometry is one of the branches of mathematics that deals with the relationship between the sides of a triangle (right triangle) with its angles".
For the given situation,
Length of guidewire = 108 meters
Angle of elevation = 42.3 degrees
Height of the antenna be 'h'.
By Pythagoras theorem,
[tex]Sine[/tex] θ = [tex]\frac{Perpendicular}{hypotenuse}[/tex]
On substituting the above values,
⇒ [tex]Sine 42.3 = \frac{h}{108}[/tex]
⇒ [tex]0.6730 =\frac{h}{108}[/tex]
⇒ [tex]h=0.6730[/tex] × [tex]108[/tex]
⇒ [tex]h= 72.68[/tex]
Hence we can conclude that the height of the antenna is 72.68 meters.
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try more
complete the statement
1. Volume of pyramid= ________× volume of rectangular prism, V= l×w×h
So for pyramid, V= 1/3 (l×w×h) = (l×w×h) ÷ ________.
2. The volume of the cylinder is three times the volume of the cone or the volume of the is _________ that of the cylinder.
3. Volume of the cone = ________ volume of the cylinder.
4. Sphere's volume is 2/3 of the _________ volume.
please answer this questions because this is need to pass tomorrow!!
1. Volume of pyramid= One third× volume of rectangular prism, V= l×w×h
So for pyramid, V= 1/3 (l×w×h) = (l×w×h) ÷ 3.
2. The volume of the cylinder is three times the volume of the cone or the volume of the cone is one third that of the cylinder.
3. Volume of the cone = One third of volume of the cylinder.
4. Sphere's volume is 2/3 of the Cylinder's volume.
Answered by GAUTHMATH
Х/10 is between 1/5
and 0.6. What could the value of x be?
Answer:
2 < x < 6
Step-by-step explanation:
x/10
1/5 = 2/10
.6 = 6/10
2 < x < 6
Which of the following numbers are less than -0.65? Select all that apply.
-0.99
-4/5
-1/6
NEXT QUESTION
Answer -0.99 and -4/5
Step-by-step explanation:
-4/5 is equal to -0.8
Both -0.8 and 0.99 are to the left of -0.65, which is why they're less than 0.65.
1/6 = -0.16
Since -0.16 is to the right of -0.65 it is more than, not less
My reason:
As you go rightward, you increase the numbers by 1, which is why the numbers closer to the right are bigger than the numbers closer to the left.
(sorry for answering when it's already been two weeks lol. I felt the urge to answer-)
I need help finding this solution.
9514 1404 393
Answer:
-16∛2
Step-by-step explanation:
It can be helpful to have some familiarity with the cubes of small integers. For example, ...
2³ = 8
6³ = 216
With this in mind you recognize the expression as ...
3∛((-6)³(2)) +∛((2³)(2))
= 3(-6)∛2 +2∛2
= (-18 +2)∛2
= -16∛2
An elected government official is interested in the opinion of teachers in her voting area. She randomly selected five schools at random from the 20 schools in her area and then interviews each of the teachers in those five schools. The government official is using
Answer:
a simple random sample (SRS).
Step-by-step explanation:
In Statistics, sampling can be defined as a process used to collect or select data (objects, observations, or individuals) from a larger statistical population using specific procedures.
There are various types of sampling used by researchers and these are;
1. Systematic sampling.
2. Convenience sampling.
3. Stratified sampling.
4. Cluster sampling.
5. Random sampling.
Random sampling also referred to as simple random sample (SRS) involves randomly selecting a subset of a larger population.
In this scenario, an elected government official randomly selected five schools at random from the 20 schools in her area and then interviews each of the teachers in those five schools, in order to get their opinions about voting. Thus, the government official is using a simple random sample (SRS).
Solve: |4x+3|=|2x+1|
Step-by-step explanation:
|4x+3|=|2x+1|THERE ARE TWO UNIQUE EQUATIONs
4x+3=2x+1
2x=-2
x=-1
(or)
4x+3= -(2x+1)
4x+3=-2x-1
6x=-4
x=-2/3
Therefore x=-1 , -2/3Solve using the elimination method. 2x + 7y = 36
6x - 7y = - 60
Answer:
[tex]x=-3[/tex]
[tex]y=6[/tex]
Step-by-step explanation:
Elimination method:
[tex]2x+7y=36[/tex]
[tex]6x-7y=-60[/tex]
Add these equation to eliminate y:
[tex]8x=-24[/tex]
Then solve [tex]8x=-24[/tex] for x:
[tex]8x=-24[/tex]
[tex]\frac{8x}{8} =\frac{-24}{8}[/tex]
[tex]x=-3[/tex]
Add the value of x to solve y:
[tex]2x+7y=36[/tex]
Substitute [tex]-3[/tex] for x in [tex]2x+7y=36[/tex]
[tex](2)(-3)+7y=36[/tex]
[tex]7y-6=36[/tex]
[tex]7y=36+6[/tex]
[tex]7y=42[/tex]
[tex]y=42/7\\[/tex]
[tex]y=6[/tex]
{ [tex]x=-3[/tex] and [tex]y=6[/tex] }
hope this helps....
HELP ME ASAP a is the blue line. B is the purple line. C is the orange line. And D is the green line
Answer: D (Green)
Step-by-step explanation:
Answer:
Step-by-step explanation:
There should be three others
<DPB
<APC
And the acute angle at D going up and to the right. It's not lettered so I can give it as an answer. I have no idea what the colors mean.
Zero is not a real number True or
False
???????????????????????????
Answer:
y-(-20)=1(x-(-10))
Step-by-step explanation:
If you're really in college you should know this, but here's the explanation:
m= -9-(-20)
1-(-10)
= 11
11
m = 1
The equation is y-y^1=m(x-x^1)
Replace the y^1, m, and x^1 from the first point
You get y-(-20)=1(x-(-10))
Or simplify that into y+20=x+10
You can also simplify it more but I don't think you need that for that question
If 89 babies are sampled at random from the hospital, what is the probability that the mean weight of the sample babies would differ from the population mean by less than 48 grams
Answer:
0.6836
Step-by-step explanation:
(weight - mean weight) = 48
Variance, s² = 204,304
Sample size, n = 89
We need to obtain the Zscore :
Zscore = (X - mean) / standard Error
Zscore = (weight - mean weight ) / (s/√n)
s = √204304 = 452
The difference from the meanncoukdnbe either to the right or left :
Zscore = - 48 / (452/√89) OR 48 / (452/√89)
Zscore = - 48 / 47.911904 OR - 48 / 47.911904
Zscore = - 1.002 or 1.002
P(Z < - 1.002) = 0.1582 (using Z table)
P(Z < 1.002) = 0.8418
P(Z < 1.002) - P(Z < - 1.002)
0.8418 - 0.1582
= 0.6836
A student selecting 3 classes for Winter quarter there are 4 drawing and design courses 3 general education courses and 3 other majors that can fit in their schedule it said student is only taking one course from each category determine the number of possible class schedules
Answer:
36 possible class schedules
Step-by-step explanation:
1st - 4 ways
2nd - 3 ways
3rd - 3 ways
4 x 3 x 3 = 36 possible class schedules
The number of possible class schedules is 36.
What is a permutation?The number of possible arrangements for a given set is calculated mathematically, and this process is known as permutation. Simply said, a permutation is a term that refers to the variety of possible arrangements or orders. The arrangement's order is important when using permutations.
Given:
A student selecting 3 classes for Winter quarter.
There are 4 drawing and design courses, 3 general education courses and 3 other majors that can fit in their schedule,
it said student is only taking one course from each category.
The possible class schedules,
= 4 x 3 x 3
= 36 possible ways.
Therefore, there are 36 possible ways.
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Suppose these data show the number of gallons of gasoline sold by a gasoline distributor in Bennington, Vermont, over the past 12 weeks.
Week Sales (1,000s of gallons)
1 17
2 22
3 20
4 24
5 18
6 17
7 21
8 19
9 23
10 21
11 16
12 23
(a) Using a weight of
1
2
for the most recent observation,
1
3
for the second most recent observation, and
1
6
for third most recent observation, compute a three-week weighted moving average for the time series. (Round your answers to two decimal places.)
Compute four-week and five-week moving averages for the time series.
Week Time Series Moving
Value Average Forecast
1 17
2 22
3 20
4 24
5 18
6 17
7 21
8 19
9 23
10 21
11 16
12 23
(b) Compute the MSE for the four-week moving average forecasts. (Round your answer to two decimal places.)
Compute the MSE for the five-week moving average forecasts. (Round your answer to two decimal places.)
(c) What appears to be the best number of weeks of past data (three, four, or five) to use in the moving average computation? MSE for the three-week moving average is 11.12.
Answer:
Use suitable identity to find the product (3-2x)(3+2x).Find the remainder when x³+ 3x²+3x+1 is divided by x+1.On a plane surface we can find straight lines.8√15 + 2√3The decimal form of 36 100(a-b)³ = a ³- ........ 3 + 3ab²-b³In the Cartesian plane the horizontal line is called .........The coefficient of x² in 2-x²+ x³ is -1.√225 is an irrational number.The coordinates of a point on x-axis is (y, 0).The coordinates of a point on x-axis is (y, 0).The coordinates of a point on x-axis is (y, 0).The coordinates of a point on x-axis is (y, 0).
How many boxes could you stack safely on a pallet if the pallet is 5 feet deep, five feet across, every box. is 1 x 1 and the maximum safe stacking height is 5 boxes? *
Answer:
25 boxes could be stacked safely on the pallet.
Step-by-step explanation:
To determine how many boxes could you stack safely on a pallet if the pallet is 5 feet deep, five feet across, every box is 1 x 1 and the maximum safe stacking height is 5 boxes, the following calculation should be performed:
Pallet = 5 x 5 = 25 square feet
Box = 1 x 1 = 1 square foot
25/1 = 25
Therefore, 25 boxes could be stacked safely on the pallet.
If three sandwiches and two bags of chips cost
$22.00, and two sandwiches and one bag of chips
cost $14.25, how much does a bag of chips cost?
Answer:
Chips: 1.25 and Sandwiches: 6.5
Step-by-step explanation:
3s+2c=22
2s+c=14.25
The cost of bag and chips should be 1.25 and 6.5.
The calculation is as follows:3s+2c=22
2s+c=14.25
Here we need to multiply by 2 in equation 2
3s + 2c = 22
2s + 2c = 28.25
s = 6.5
Now
c should be
2(6.5) + c = 14.25
13 + c = 14.25
c = 1.25
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You return from a trip with 480 Canadian dollars. How much are your Canadian dollars worth in U.S. dollars? Use the exchange rate shown below. Currency U.S. dollars per Canadian dollar Canadian dollars per U.S. dollar Canadian dollar 0.5823 1.717 The 480 Canadian dollars are equivalent to about $ (Round to the nearest cent as needed.)
591 Dollars 42 Cents (591 Dollars when rounded)
find the first three common multiplies
6 and 8
Answer:
24,48,72
Step-by-step explanation:
multiples of 6- 6,12,18,24,30,36,42,48,54,60,66,72
multiples of 8- 8,16,24,32,40,48,56,64,74,80
(a) What is the probability that a person who was polled prefers chocolate ice cream to vanilla? Round your answer to four decimal places.
Answer:
[tex]P(k)=0.2628[/tex]
Step-by-step explanation:
Given
[tex]n = 1693[/tex] --- sample size
[tex]k = 445[/tex] --- those that prefer chocolate ice cream to vanilla
Required
[tex]P(k)[/tex]
This is calculated as:
[tex]P(k)=\frac{k}{n}[/tex] --- probability formula
So, we have:
[tex]P(k)=\frac{445}{1693}[/tex]
[tex]P(k)=0.2628[/tex]
can anyone help me with this an explain
Answer:
si a forse that can t negativo AND f so ITS 0;3
You want to make a playlist with all different songs. How many ways can you make a playlist of 16 songs if you must play Leavon, Dream on, Here Comes the Sun, and Clocks in that order?
Answer in permutations
Answer: [tex]_{13} P _{13}[/tex]
Another acceptable answer is 13! where the exclamation mark is needed.
The numeric form is 6,227,020,800 which is a little over 6 billion.
==============================================================
Explanation:
Let's lump those four songs together to form a so called "mega song". So we treat those four items as one single item. This is ensure that those songs are played in the order we want. The other songs aren't treated this way.
We start with 16 songs and drop to 16-4 = 12 songs when taking out those four named songs. Then we add 1 to get 12+1 = 13 since we're adding in that "mega song" block.
---------------------------
So to recap so far, we've gone from 16 songs to 13 songs. The goal is to find out how many arrangements of 13 songs are possible. Order matters.
We'll use the nPr permutation function
[tex]_{n} P _{r} = \frac{n!}{(n-r)!}\\\\[/tex]
where in this case n = 13 and r = 13. Your teacher doesn't want you to evaluate this function. You simply need to state the symbolic form. So that's why we go from [tex]_{n} P _{r}[/tex] to [tex]_{13} P _{13}[/tex]
If you wanted to answer this in terms of factorial notation, then you could say this
[tex]_{n} P _{r} = \frac{n!}{(n-r)!}\\\\_{13} P _{13} = \frac{13!}{(13-13)!}\\\\_{13} P _{13} = \frac{13!}{(0)!}\\\\_{13} P _{13} = \frac{13!}{1}\\\\_{13} P _{13} = 13!\\\\[/tex]
So we can see that the notations [tex]_{13} P _{13}[/tex] and [tex]13![/tex] mean the exact same thing.
If you wanted to know the actual number of permutations, then,
13! = 13*12*11*10*9*8*7*6*5*4*3*2*1 = 6,227,020,800
which is a little over 6 billion permutations.
Find the inverse of the given function. (pictured below)
Answer:
4
3
0
Step-by-step explanation:
f(x) = y = -1/2 × sqrt(x+3)
2y = -sqrt(x+3)
4y² = x + 3
x = 4y² - 3
now renaming this, so that the normal symbols and names are used for this function definition, so that the input variable is called "x" :
f-1(x) = 4x² - 3
basically, just by itself, this function would be defined for all possible real values of x.
but because it is the inverse of the original function, which generates only values of y<=0, then for the inverse function that same range applies for its input variable x
x<=0
Solve the formula for t
Answer:
Step-by-step explanation:
S - 4πc^2 = 6πct
t = (S - 4πc^2)/6πc
t = S/(6πc) - 2/3 c
assuming c ≠ 0
T=3 and t=5 to determine if the expression 4(t+3) and 4 t+12 are equivalent
Write the range of the function using interval notation.
Answer:
[-3, -1]
Step-by-step explanation:
The minimum y value is -3.
The maximum y value is -1.
-3 and -1 are included, so we use square brackets.
Answer: [-3, -1]
In a town. the population of registered voters is 46% democrat, 42% republican and 12% independent polling data shows 57% of democrats support the increase , 38% of republicans support the increase, and 76% of independents support the increase.
Required:
a. Find the probability that a randomly selected voter in the town supports the tax increase.
b. What is the probability that a randomly selected voter does not support the tax increase?
c. Suppose you find a voter at random who supports the tax increase. What is the probability he or she is a registered Independent?
Answer:
a) 0.513 = 51.3% probability that a randomly selected voter in the town supports the tax increase.
b) 0.487 = 48.7% probability that a randomly selected voter does not support the tax increase.
c) 0.1777 = 17.77% probability he or she is a registered Independent.
Step-by-step explanation:
Conditional Probability
We use the conditional probability formula to solve this question. It is
[tex]P(B|A) = \frac{P(A \cap B)}{P(A)}[/tex]
In which
P(B|A) is the probability of event B happening, given that A happened.
[tex]P(A \cap B)[/tex] is the probability of both A and B happening.
P(A) is the probability of A happening.
Question a:
57% of 46%(democrats)
38% of 42%(republicans)
76% of 12%(independents)
So
[tex]P = 0.57*0.46 + 0.38*0.42 + 0.76*0.12 = 0.513[/tex]
0.513 = 51.3% probability that a randomly selected voter in the town supports the tax increase.
Question b:
1 - 0.513 = 0.487
0.487 = 48.7% probability that a randomly selected voter does not support the tax increase.
c. Suppose you find a voter at random who supports the tax increase. What is the probability he or she is a registered Independent?
Event A: Supports the tax increase.
Event B: Is a independent.
0.513 = 51.3% probability that a randomly selected voter in the town supports the tax increase.
This means that [tex]P(A) = 0.513[/tex]
Probability it supports a tax increase and is a independent:
76% of 12%, so:
[tex]P(A \cap B) = 0.76*0.12[/tex]
Thus
[tex]P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{0.76*0.12}{0.513} = 0.1777[/tex]
0.1777 = 17.77% probability he or she is a registered Independent.
How do I do this equation
This question requires the manipulation of the Ideal Gas formula. By moving the variables around, you'll get :
V = nRT/P
n = PV/RT
Use cross products to identify the equation needed to solve this proportion:
5
x
=
2
9
Answer:
x=22.5
Step-by-step explanation:
We are given the proportion:
5/x=2/9
Cross multiply. Multiply the numerator (top number) of the first fraction by the denominator (bottom number) of the second. Then multiply the denominator of the first by the numerator of the second.
5*9=2*x
45=2x
2 and x are being multiplied. The opposite of multiplication is division. Divide both sides by 2. This will cancel out the 2 being multiplied by x, and leave x by itself.
45/2=2x/2
45/2=x
22.5=x
If we substitute 22.5 in for x, the final proportion will be:
5/22.5=2/9
