Answer:
Null hypothesis: [tex]\mu_1= \mu_2[/tex]
Alternative hypothesis:[tex]\mu_1 =\neq \mu_2[/tex]
And for this case we assume that we have equal variances so that means:
[tex]\sigma =\sigma_1 =\sigma_2[/tex]
For this case the degrees of freedom are given by:
[tex] df= n_1 +n_2 -2[/tex]
And replacing we got:
[tex] df= 20+20 -2= 38[/tex]
And the best answer would be:
a. 38
Step-by-step explanation:
For this problem we want to test the following:
Null hypothesis: [tex]\mu_1= \mu_2[/tex]
Alternative hypothesis:[tex]\mu_1 =\neq \mu_2[/tex]
And for this case we assume that we have equal variances so that means:
[tex]\sigma =\sigma_1 =\sigma_2[/tex]
For this case the degrees of freedom are given by:
[tex] df= n_1 +n_2 -2[/tex]
And replacing we got:
[tex] df= 20+20 -2= 38[/tex]
And the best answer would be:
a. 38
[PLEASE HELP] Each of these statements describe a transformation of a graph of y = x, The which of the statements correctly describe the graph of y =x + 7???
Answer:
B
Step-by-step explanation:
Adding the 7 to the input (x) will increase the output (y) by 7. Therefore, the graph is translated 7 units up.
Answer:
The answer is B
Step-by-step explanation:
well the equation of a line is : y = mx + b
in this question the equation is y = x
so the line y = x +7 will be 7 units up than y = x
Not sure how I would find the quadrant
1. Lisa is a regional manager for a restaurant chain that has locations in the towns of Berwick, Milton, and Leesburg. She would like to investigate if a difference exists in the proportion of customers who rate their experience as satisfactory or better between the three locations. The following data represent the number of customers who indicated they were satisfied from random samples taken at each location.
Berwick Milton Leesburg
Number Satisfied 80 85 60
Sample Size 100 120 80
The expected frequency of satisfied customers from the Berwick sample is________.
a. 60
b. 75
c. 80
d. 90
2. Lisa is a regional manager for a restaurant chain that has locations in the towns of Berwick, Milton, and Leesburg. She would like to investigate if a difference exists in the proportion of customers who rate their experience as satisfactory or better between the three locations. The following data represent the number of customers who indicated they were satisfied from random samples taken at each location.
Berwick Milton Leesburg
Number Satisfied 80 85 60
Sample Size 100 120 80
The expected frequency of satisfied customers from the Milton sample is________.
a. 60
b. 75
c. 80
d. 90
3. Lisa is a regional manager for a restaurant chain that has locations in the towns of Berwick, Milton, and Leesburg. She would like to investigate if a difference exists in the proportion of customers who rate their experience as satisfactory or better between the three locations. The following data represent the number of customers who indicated they were satisfied from random samples taken at each location.
Berwick Milton Leesburg
Number Satisfied 80 85 60
Sample Size 100 120 80
The expected frequency of satisfied customers from the Leesburg sample is________.
a. 60
b. 75
c. 80
d. 90
4. Lisa is a regional manager for a restaurant chain that has locations in the towns of Berwick, Milton, and Leesburg. She would like to investigate if a difference exists in the proportion of customers who rate their experience as satisfactory or better between the three locations. The following data represent the number of customers who indicated they were satisfied from random samples taken at each location.
Berwick Milton Leesburg
Number Satisfied 80 85 60
Sample Size 100 120 80
The chi-square test statistic for these samples is_______.
a. 1.49
b. 2.44
c. 4.15
d. 5.33
5. Lisa is a regional manager for a restaurant chain that has locations in the towns of Berwick, Milton, and Leesburg. She would like to investigate if a difference exists in the proportion of customers who rate their experience as satisfactory or better between the three locations. The following data represent the number of customers who indicated they were satisfied from random samples taken at each location.
Berwick Milton Leesburg
Number Satisfied 80 85 60
Sample Size 100 120 80
The degrees of freedom for the chi-square critical value is_______.
a. 1
b. 2
c. 3
d. 4
6. Lisa is a regional manager for a restaurant chain that has locations in the towns of Berwick, Milton, and Leesburg. She would like to investigate if a difference exists in the proportion of customers who rate their experience as satisfactory or better between the three locations. The following data represent the number of customers who indicated they were satisfied from random samples taken at each location.
Berwick Milton Leesburg
Number Satisfied 80 85 60
Sample Size 100 120 80
The chi-square critical value using alpha = 0.05 is_______.
a. 2.706
b. 3.841
c. 5.991
d. 7.815
7. Lisa is a regional manager for a restaurant chain that has locations in the towns of Berwick, Milton, and Leesburg. She would like to investigate if a difference exists in the proportion of customers who rate their experience as satisfactory or better between the three locations. The following data represent the number of customers who indicated they were satisfied from random samples taken at each location.
Berwick Milton Leesburg
Number Satisfied 80 85 60
Sample Size 100 120 80
Using alpha = 0.05, the conclusion for this chi-square test would be that because the test statistic is
A. More than the critical value, we can reject the null hypothesis and conclude that there is a difference in proportion of satisfied customers between these three locations.
B. Less than the critical value, we can reject the null hypothesis and conclude that there is a difference in proportion of satisfied customers between these three locations.
C. More than the critical value, we fail to reject the null hypothesis and conclude that there is no difference in proportion of satisfied customers between these three locations.
D. Less than the critical value, we fail to reject the null hypothesis and conclude that there is no difference in proportion of satisfied customers between these three locations.
Answer:
1) Option B is correct.
Expected frequency of satisfied customers from the Berwick sample = 75
2) Option D is correct.
Expected frequency of satisfied customers from the Milton sample = 90
3) Option A is correct.
Expected frequency of satisfied customers from the Leesburg sample = 60
4) Option B is correct.
The chi-square test statistic for these samples = 2.44
5) Option B is correct.
The degrees of freedom for the chi-square critical value = 2
6) Option C is correct.
The chi-square critical value using alpha = 0.05 is 5.991
7) Option D is correct.
The conclusion for this chi-square test would be that because the test statistic is less than the critical value, we fail to reject the null hypothesis and conclude that there is no difference in proportion of satisfied customers between these three locations.
Step-by-step explanation:
Berwick Milton Leesburg
Number Satisfied 80 85 60
Unsatisfied 20 35 20
Sample Size 100 120 80
Since this is a chi test that aims to check if there are differences in the proportion of expected number of customers for each location, we state the null and alternative hypothesis first.
The null hypothesis usually counters the claim we hope to test and would be that there is no difference between the proportion of expected frequency of satisfied customers at the three locations.
The alternative hypothesis confirms the claim we want to test and is that there is a significant difference between the proportion of expected frequency of satisfied customers at the three locations.
So, the total proportion of satisfied customers is used to calculate the expected number of satisfied customers for each of the three locations.
80+85+60= 225
Total number of customers = 100 + 120 + 80 = 300
Proportion of satisfied customers = (225/300) = 0.75
1) Expected frequency of satisfied customers from the Berwick sample = np = 100 × 0.75 = 75
2) Expected frequency of satisfied customers from the Milton sample = np = 120 × 0.75 = 90
3) Expected frequency of satisfied customers from the Leesburg sample = np = 80 × 0.75 = 60
4) Berwick Milton Leesburg
Number Satisfied 80 85 60
Unsatisfied 20 35 20
Sample Size 100 120 80
Proportion for unsatisfied ccustomers = 0.25
So, expected number of unsatisfied customers for the three branches are 25, 30 and 20 respectively.
Chi square test statistic is a sum of the square of deviations from the each expected value divided by the expected value.
χ² = [(X₁ - ε₁)²/ε₁] + [(X₂ - ε₂)²/ε₂] + [(X₃ - ε₃)²/ε₃] + [(X₄ - ε₄)²/ε₄] + [(X₅ - ε₅)²/ε₅] + [(X₆ - ε₆)²/ε₆]
X₁ = 80, ε₁ = 75
X₂ = 85, ε₂ = 90
X₃ = 60, ε₃ = 60
X₄ = 20, ε₄ = 25
X₅ = 35, ε₅ = 30
X₆ = 20, ε₆ = 20
χ² = [(80 - 75)²/75] + [(85 - 90)²/90] + [(60 - 60)²/60] + [(20 - 25)²/25] + [(35 - 30)²/30] + [(20 - 20)²/20]
χ² = 0.3333 + 0.2778 + 0 + 1 + 0.8333 + 0 = 2.4444 = 2.44
5) The degree of freedom for a chi-square test is
(number of rows - 1) × (number of columns - 1)
= (2 - 1) × (3 - 1) = 1 × 2 = 2
6) Using the Chi-square critical value calculator for a degree of freedom of 2 and a significance level of 0.05, the chi-square critical value is 5.991.
7) Interpretation of results.
If the Chi-square test statistic is less than the critical value, we fail to reject the null hypothesis.
If the Chi-square test statistic is unusually large and is greater than the critical value, we reject the null hypothesis.
For this question,
Chi-square test statistic = 2.44
Critical value = 5.991
2.44 < 5.991
test statistic < critical value
The test statistic is Less than the critical value, we fail to reject the null hypothesis and conclude that there is no difference in proportion of satisfied customers between these three locations.
Hope this Helps!!!
A cylinder fits inside a square prism as shown. For every
cross section the ratio of the area of the circle to the
area of the square is on
since the area of the circle is the area of the square,
the volume of the cylinder equals
Cross section
o
o
o
o
the volume of the prism or (20(h) or turh.
the volume of the prism or (47)(h) or 2nuh.
the volume of the prism or (20)(h) or Ph.
the volume of the prism or (47)(h) or iPh.
kl *
Answer:
Volume of cylinder = π/4 (the volume of the prism) or π/4 (4r²)(h) or πr²h (D)
The complete question related to this found on brainly (ID: 4049983 and 4265826) is stated below:
A cylinder fits inside a square prism as shown. For every cross section, the ratio of the area of the circle to the area of the square is or πr^2 or π/4. Since the area of the circle is π/4 the area of the square, the volume of the cylinder equals
A) π/2(the volume of the prism) or π/2 (2r)(h) or πrh.
B) π/2 (the volume of the prism) or π/2 (4r2)(h) or 2πrh.
C) π/4(the volume of the prism) or π/4 (2r)(h) or π/4(r2h).
D) π/4(the volume of the prism) or π/4 (4r2)(h) or πr2h.
See attachment for diagram
Step-by-step explanation:
Area of the cross section in the cylinder
Area of circle = πr²
Area of the cross section in the square prism
Area of square = (side length)²
Here the side length = diameter
Diameter = 2×radius = 2r
Area of square = (2r)² = 4r²
Ratio of area of circle to area of square = πr²/4r² = π/4
Area of circle/area of square = π/4
Area of circle = π/4 × area of square
Area of circle = π/4 × 4r²
Volume of cylinder = area of circle × height
Volume = πr² ×h = πr²h
Volume of square prism = area of square × height = (2r)²h = 4r²h
Ratio of volume of cylinder to volume of square prism = πr²h/4r²h = π/4
Volume of cylinder/volume of square prism = π/4
Volume of cylinder = π/4 × volume of square prism = π/4 × 4r²h
= πr²h
Therefore Volume of cylinder = π/4 (the volume of the prism) or π/4 (4r²)(h) or πr²h (D)
www.g A survey of athletes at a high school is conducted, and the following facts are discovered: 19% of the athletes are football players, 79% are basketball players, and 14% of the athletes play both football and basketball. An athlete is chosen at random from the high school: what is the probability that they are either a football player or a basketball player
Answer:
84%
Step-by-step explanation:
The probability that the selected player is a football player, P(F)=19%
The probability that the selected player is a basketball player, P(B)=79%
The probability that the selected player play both football and basketball,
[tex]P(B \cap F)=14\%[/tex]
We want to determine the probability that a randomly chosen athlete is either a football player or a basketball player, [tex]P(B \cup F)[/tex]
In probability theory
[tex]P(B \cup F)=P(B)+P(F)-P(B \cap F)\\=79\%+19\%-14\%\\=84\%[/tex]
The probability that a randomly chosen athlete is either a football player or a basketball player is 84%.
3. Find the measure of x.
a 18°
b. 54°
C 126
d. 45
Answer:
18 degrees
Step-by-step explanation:
The triangle is an iscoceles right triangle.
The angles in a triangle add up to 180.
90+2y (iscoceles) =180
2y=90
y=45
So the angles of the right triangle are 45. However, you have to take away 27 because you are solving for only a part of 45. 45-27=18
Number of non sqaure number are there between 36² and 37²
Answer:
A 1,296
B 1,369
36 answer
Want Brainliest? Get this correct Which of the following is the product of the rational expressions shown below?
We multiply the numerators together to get x*2x = 2x^2 as the numerator for the answer.
The denominators pair up and multiply to get (x-5)(x+4) = x^2+4x-5x-20 = x^2-x-20. You can use the distributive property, FOIL, or the box method to expand out (x-5)(x+4)
So that's how we end up with (2x^2) all over (x^2-x-20) as the answer.
Nine balls, each marked with a number from 1 to 9, are placed in a bag and one
Ball is taken out at random. What is the probability that the number on the ball is:
(a) odd, (b) a multiple of 3, (c) 5, (d) not a 7
Answer:
a =5/9 b=1/3 c=1/9 d=8/9
Step-by-step explanation:
there are total 9 numbers
in a
there are 5 odd numbers
in b
there are 3 multiplier of 3
in c
there is only one 5
in d
there are 8 numbers except 7
a) 5/9 b) 1/3 c) 1/9 d) 8/9
Step-by-step explanation:
a) odd numbers between 1 to 9 are 1,3,5,7,9. so there are 5 odd numbers.
total balls are 9
=> probability is 5/9
b) multiples of 3 = 3, 6,9 there are 3 numbers.
=> probability is = 3/9 = 1/3
c) 5. only one 5 is there between 1 to 9 numbers.
=> probability is 1/9
d) not a 7.
removing 7. there will 8 numbers.
=> probability is 8/9
g A catering service offers 7 %E2%80%8b Appetizers, 9 main%E2%80%8B courses, and 5 desserts. A banquet committee is to select 2 %E2%80%8b Appetizers, 8 main%E2%80%8B courses, and 4 desserts. How many ways can this be%E2%80%8B done
Answer:
945 ways
Step-by-step explanation:
Total
Number of Appetizers = 7Number of main courses = 9Number of desserts =5Required Selection
Number of Appetizers = 2Number of main courses = 8Number of desserts =42 Appetizers out of 7 can be selected in [tex]^7C_2[/tex] ways
8 main courses out of 9 can be selected in [tex]^9C_8[/tex] ways
4 desserts out of 5 can be selected in [tex]^5C_4[/tex] ways
Therefore, the number of ways this can be done
[tex]=^7C_2 \times ^9C_8 \times ^5C_4[/tex]
=945 ways
Find the value of x geometry
Answer:
x = 22
Step-by-step explanation:
Since the the 2 bisectors are equal, that means the chords are also equal. Since bisector splits into 2 equal parts, 11 + 11 equals 22
Which of the following statements about trapezoids is true?
O A. Opposite angles are equal
B. One pair of opposite sides is paralel.
C. Opposite sides are equal
O D. Both pairs of opposite sides are parallel
Answer:
B
Step-by-step explanation:
Trapezoids have only one pair of parallel lines.
If f(x)=2x−1, show that f(f(x))=4x−3. Find f(f(f(x))).
Answer: f(f(f(x)))=8x-7
Step-by-step explanation:
Since we were given f(x) and f(f(x)), We plug that into f(x) again to get f(f(f(x))).
2(4x-3)-1 [distribute]
8x-6-1 [combine like terms]
8x-7
i need this asap guys im giving brainliest
An aquarium is in the shape of a rectangular prism. How much water will it take to fill the aquarium if the dimensions are 2ft by 4ft by 3ft? 12 cubic feet 24 cubic feet 36 cubic feet 8 cubic feet
Answer:
24 cubic feet.
Step-by-step explanation:
What we need to do here, is to find the volume of the aquarium.
The Aquarium is a rectangular prism.
The volume of a rectangular prism is length*width*height (we just multiply the dimensions together)
2*4*3=8*3=24
The volume of the aquarium is 24 cubic feet, and therefore 24 cubic feet of water is required to fill the tank.
Answer:
Hello! :) The answer will be under “Explanation”
Step-by-step explanation:
The answer will be 24 cubic feet.
Work:
LxWxH
(Length,Width,Hight)
So you the question is asking about volume, we need to do the formula (length,width, and hight)
Now we have to multiply
2x4=8
8x3=24
So the answer will be 24 cubic feet.
Hope this helps! :)
make d the subject of the formula; n=k/d^2
Answer:
[tex]n = \frac{k}{ {d}^{2} } [/tex]
[tex] {d}^{2} = \frac{k}{n} [/tex]
[tex]d = \sqrt{ \frac{k}{n} } [/tex]
Here is the required firmula....Answer:
d = √(k/n)
Step-by-step explanation:
n = k/d²
n/1 = k/d²
Cross multiply.
k = nd²
Divide both sides by n.
k/n = nd²/n
k/n = d²
Take the square root on both sides.
√(k/n) = √(d²)
√(k/n) = d
A rookie quarterback is negotiating his first NFL contract.His opportunity cost is 10%. He has been offered three possible 4-year contracts. Payments are guaranteed, and they would be made at the end of each year. Terms of each contract are as follows:________.
1 2 3 4
Contract 1 $3,000,000 $3,000,000 $3,000,000 $3,000,000
Contract 2 $2,000,000 $3,000,000 $4,000,000 $5,000,000
Contract 3 $7,000,000 $1,000,000 $1,000,000 $1,000,000
As his advisor, which contract would you recommend that he accept?
Answer:
He should accept contract 2 because it has a higher present value.
Step-by-step explanation:
we need to find the present value of each contract:
Contract 1 = $3,000,000/1.1 + $3,000,000/1.1² + $3,000,000/1.1³ + $3,000,000/1.1⁴ = $2,727,273 + $2,479,339 + $2,253,944 + $2,049,040 = $9,509,596
Contract 2 $2,000,000/1.1 + $3,000,000/1.1² $4,000,000/1.1³ + $5,000,000 /1.1⁴ = $1,818,182 + $2,479,339 + $3,005,259 + $3,415,067 = $10,717,847
Contract 3 $7,000,000/1.1 + $1,000,000/1.1² + $1,000,000/1.1³ + $1,000,000/1.1⁴ = $6,363,636 + $826,446 + $751,315 + $683,013 = $8,624,410
Which of the following is a secant on the circle below?
DE is secant on the circle below.
What is Secant?A secant line is a straight line that twice intersects a circle.
We have a diagram of circle.
As, Either a secant or a tangent will arise from the circle's junction.
A secant is a line that intersects a circle twice. The relationship between the circle and the line that intersects it is explained by this idea.
Again from the figure CA and CE intersect circle at B and D.
It can also represented that the AB and DE intersects at a point C.
So, the secant line that intersects the circle twice.
Learn more about Secant here:
https://brainly.com/question/14348796
#SPJ7
20. The profit of a company increased steadily over a ten-year span. The following ordered pairs show the number of units sold in hundreds and the profit in thousands of units over the ten-year span, (number of units sold, profit) for specific recorded years: (46,250), (48, 305), (50,350), (52, 390), (54, 410) a) Use linear regression to determine a function y, where profit in thousands of dollars depends on the number of units sold in hundreds. b) Predict when the profit will exceed one million dollars.
Answer:
20
Step-by-step explanation:
The linear function represents the number of units sold y in terms of profit x is y = 27.5x - 1015.
What is a linear function?
A straight line on the coordinate plane is represented by a linear function.
A linear function always has the same and constant slope.
The formula for a linear function is f(x) = ax + b, where a and b are real values.
As per the given pair of (number of units sold y, profit x)
Linear equation slope and y-intercept
A linear equation or function is given as ;
y = mx + c
Here, c is the y-intercept and m is the slope.
The slope associated with two points (x₁, y₁) and (x₂, y₂) is given by
Slope m = (y₂ - y₁)/(x₂ - x₁)
Therefore slope of (46,250), (48, 305)
m = (305 - 250)/(48 - 46) = 27.5
Put, m = 27.5 and (46,250)
250 = 27.5(46) + c
c = -1015
y = 27.5x - 1015
Hence "The linear function represents the number of units sold y in terms of profit x is y = 27.5x - 1015".
For more about the linear function,
brainly.com/question/21107621
#SPJ2
A rectangle is placed around a semicircle as shown below. The length of the rectangle is 12 cm. Find the area of the shaded region.
Use the value 3.14 for at, and do not round your answer. Be sure to include the correct unit in your answer.
Answer:
15.48 ft^2
Step-by-step explanation:
According to the image we have the following information:
the length of the rectangle = diameter of the semicircle, therefore it is 12 feet
, the radius of the semicircle (half the diameter) = width of the rectangle = 12/2 ft = 6 ft
We also know that the area of the shaded region would be equal to the area of the rectangle minus the area of the semicircle.
Therefore, we replace:
Area of the rectangle = width * length
Ar = 6 ft * 12 ft = 72 ft ^ 2
Area of the semicircle = [1/2] * π * (r ^ 2)
As = [1/2] * 3.14 * (6 feet) ^ 2 = 56.52 ft ^ 2
We replace in the area of the shaded region
shaded region area = 72 ft ^ 2 - 56.52 ft ^ 2 =
Shaded region area = 15.48 ft ^ 2
Which is a possible paycheck deduction? Select all that apply.
commission
federal income tax
health insurance premium
overtime hours
state income tax
Answer:
Federal income taxes, health insurance premium, state income tax
Step-by-step explanation:
Commission may be a bonus from a sale you made and overtime hours are extra hours over 40.00 that you worked during the week
2 things are certain in life death and taxes
plz answer question in screen shot
Answer: 342.32
Step-by-step explanation: sin(25) = h/a
Sin(25)= h/27
27*sin(25) = h
b*h = area
I need help plz someone help me solved this problem I need help ASAP! I will mark you as brainiest!
Answer: (a) [tex]\bold{A=900\bigg(1+\dfrac{0.07}{4}\bigg)^{4t}}[/tex]
(b) A = $1680.67
(c) t = 9.99 years
(d) A = $1689.85
Step-by-step explanation:
[tex]A=P\bigg(1+\dfrac{r}{n}\bigg)^{nt}[/tex] where
A is the amount accrued (balance)P is the principal (original/initial amount)r is the interest rate (convert to a decimal)n is the number of times compounded per yeart is the number of yearsa) Given: P = 900, r = 7% = 0.07, n = quarterly = 4
[tex]\bold{A=900\bigg(1+\dfrac{0.07}{4}\bigg)^{4t}}[/tex]
b) Given: P = 900, r = 7% = 0.07, n = quarterly = 4, t = 9
[tex]A=900\bigg(1+\dfrac{0.07}{4}\bigg)^{4(9)}\\\\\\A = 900\bigg(1+\dfrac{0.07}{4}\bigg)^{36}[/tex]
A = 1680.67
c) Given: A = 1800, P = 900, r = 7% = 0.07, n = quarterly = 4
[tex]1800=900\bigg(1+\dfrac{0.07}{4}\bigg)^{4t}\\\\\\2=\bigg(1+\dfrac{0.07}{4}\bigg)^{4t}\\\\\\ln\ 2=ln\bigg(1+\dfrac{0.07}{4}\bigg)^{4t}\\\\\\ln\ 2 = 4t\ ln\bigg(1+\dfrac{0.07}{4}\bigg)\\\\\\\dfrac{ln\ 2}{4\ ln\bigg(1+\dfrac{0.07}{4}\bigg)}=t\\\\\\\bold{t=9.99}[/tex]
d) [tex]A=Pe^{rt}[/tex]
Given: P = 900, r = 7% = 0.07, t = 9
[tex]A=900e^{0.07(9)}\\\\\\A=900e^{.63}\\\\\\\bold{A=1689.85}[/tex]
A tank contains 4,000 L of brine with 18 kg of dissolved salt. Pure water enters the tank at a rate of 40 L/min. The solution is kept thoroughly mixed and drains from the tank at the same rate.
a. How much salt is in the tank after t minutes?
b. How much salt is in the tank after 30 minutes? (Round your answer to one decimal place.
Answer:
(a)[tex]A(t)=18e^{ -\frac{t}{100}}[/tex]
(b)13.3 kg
Step-by-step explanation:
The volume of brine in the tank = 4000L
Initial Amount of salt, A(0)=18 kg
The rate of change in the amount of salt in the tank at any time t is represented by the equation:
[tex]\dfrac{dA}{dt}=$Rate In$-$Rate Out[/tex]
Rate In = (concentration of salt in inflow)(input rate of brine)
Since pure water enters the tank, concentration of salt in inflow =0
Rate In = 0
Rate Out=(concentration of salt in outflow)(output rate of brine)
[tex]=\frac{A(t)}{4000}\times 40\\ =\frac{A(t)}{100}[/tex]
Therefore:
[tex]\dfrac{dA}{dt}=-\dfrac{A(t)}{100}\\\dfrac{dA}{dt}+\dfrac{A(t)}{100}=0[/tex]
This is a linear D.E. which we can then solve for A(t).
Integrating Factor: [tex]e^{\int \frac{1}{100}d}t =e^{ \frac{t}{100}[/tex]
Multiplying all through by the I.F.
[tex]\dfrac{dA}{dt}e^{ \frac{t}{100}}+\dfrac{A(t)}{100}e^{ \frac{t}{100}}=0e^{ \frac{t}{100}}\\(Ae^{ \frac{t}{100}})'=0[/tex]
Taking integral of both sides
[tex]Ae^{ \frac{t}{100}}=C\\A(t)=Ce^{ -\frac{t}{100}}[/tex]
Recall our initial condition
A(0)=18 kg
[tex]18=Ce^{ -\frac{0}{100}}\\C=18[/tex]
Therefore, the amount of salt in the tank after t minutes is:
[tex]A(t)=18e^{ -\frac{t}{100}}[/tex]
(b)When t=30 mins
[tex]A(30)=18e^{ -\frac{30}{100}}\\=18e^{ -0.3}\\=13.3 $kg(correct to 1 decimal place)[/tex]
The amount of salt in the tank after 30 minutes is 13.3kg
In this exercise we have to use the integral to calculate the salt concentration:
(a)[tex]A(t)=18e^{-\frac{t}{100} }[/tex]
(b)[tex]13.3 kg[/tex]
Knowing that the volume of brine in the tank = 4000L, the initial Amount of salt, A(0)=18 kg. The rate of change in the amount of salt in the tank at any time t is represented by the equation:
[tex]\frac{dA}{dt} = Rate \ in - Rate \ out[/tex]
Rate In = (concentration of salt in inflow)(input rate of brine). Since pure water enters the tank, concentration of salt in inflow =0.
Rate In = 0
Rate Out=(concentration of salt in outflow)(output rate of brine)
[tex]\frac{A(t)}{4000}*(40)[/tex]
[tex]= \frac{A(t)}{100}[/tex]
Therefore:
[tex]\frac{dA}{dt} = \frac{A(t)}{100}\\\frac{dA}{dt} + \frac{A(t)}{100} = 0[/tex]
This is a linear D.E. which we can then solve for A(t). Integrating Factor: [tex]e^{\int\limits {\frac{t}{100} } \, dt\\e^{t/100}[/tex] . Multiplying all through by the Integrating Factor:
[tex]\frac{dA}{dt} = e^{t/100}+\frac{A(t)}{100}e^{t/100}\\(Ae^{1/100})'=0[/tex]
Taking integral of both sides:
[tex]Ae^{t/100}=C\\A(t)=Ce^{-t/100}[/tex]
Recall our initial condition:
[tex]A(0)=18 kg\\18=Ce^{0}\\C=18[/tex]
Therefore, the amount of salt in the tank after t minutes is:
[tex]A(t)=18e^{-t/100}[/tex]
(b)When t=30 mins
[tex]A(30)=18e^{-30/100}\\=18e^{-0.3}\\=13.3[/tex]
The amount of salt in the tank after 30 minutes is 13.3kg.
See more about concentration at brainly.com/question/12970323
Which point is located at (Negative 3.5, Negative 4.5)? On a coordinate plane, point A is 3.5 units to the left and 4.5 units down. Point K is 3.5 units to the right and 4.5 units up. Point R is 3.5 units to the left and 4.5 units up. Point Y is 4.5 units to the left and 3.5 units down. point A point K point R point Y
Answer:
Point A
Step-by-step explanation:
We know that on a coordinate plane, negative numbers can be found by moving down or moving to the left. This point must be found by moving down and left. To establish whether it is point A or point Y, we can remember that x coordinates move left and right and y coordinates move up and down. So, we would need to move 3.5 units left for x and then 4.5 units down for y. This leads us to point A.
hope this helps!
Answer:
it is point A
Step-by-step explanation:
What is y - 8 = 4(x - 4) in slope intercept form?
Answer:
y=4x-8
Step-by-step explanation:
First you must use the distributive property and get y-8=4x-16.
Then you have to add 8 on both sides so just y is left on the left side.
This will get you y=4x-8 in slope-intercept form.
To get from North to East, you walk 12 meters south and 16 meters east, as shown
in the diagram below. If you wanted to walk straight from North to East, what would
the distance be? Solve for x
Answer:
ur pito is to small
Step-by-step explanation:
it to little
forex is the name of the U.S. stock exchange.
-true
-false
Answer:
false
Step-by-step explanation:
hello
this is false
FOREX means Foreign Exchange
it refers to the foreign exchange market
hope this helps
Answer:
true, forex trading is a profitable than staking cryptocurrency. forex trading is the best thing I will refer someone I love because learning never stops and no on is above blowing accounts when beginning Forex
Now that we have our linear regression model, let’s try to make a prediction for the sales given a new set of advertising budgets as follows: new.dat <- data.frame(TV=200, Radio=10, Newspaper=20) You are required to report the predicted sales as well as the lower and upper bound for the 95% prediction interval. What will you report?
Answer:
The predicted sales for the new set of advertising budgets is 14.
Step-by-step explanation:
The linear regression model is:
[tex]\text{Sales}=2.9389+0.0458\cdot(\text{TV})+0.1885\cdot(\text{Radio})-0.0010\cdot(\text{Newspaper})[/tex]
Compute the value of sales for:
TV = 200,
Radio = 10,
Newspaper = 20
[tex]\text{Sales}=2.9389+0.0458\cdot(\text{TV})+0.1885\cdot(\text{Radio})-0.0010\cdot(\text{Newspaper})[/tex]
[tex]=2.9389+0.0458\cdot(200)+0.1885\cdot(10)-0.0010\cdot(20)\\=2.9389+9.16+1.885-0.0002\\=13.9837\\\approx 14[/tex]
Thus, the predicted sales for the new set of advertising budgets is 14.
Phil Nelson deposited $35,000 at Wachovia Bank at 3.5% interest
compounded quarterly. How much money will be in this account at
the end of the year?
Answer:
$36,241.20
Step-by-step explanation:
Compounded Interest Rate Formula: A = P(1 + r/n)^nt
Since we are given P, r, n, and t, simply plug it into the formula:
A = 35000(1 + 0.035/4)⁴⁽¹⁾
A = 35000(1 + 0.00875)⁴
A = 35000(1.00875)⁴
A = 35000(1.03546)
A = 36241.2
The price of a vase was increased by 10% to £22.What was the price before the increase
Answer: £20.
Step-by-step explanation:
Let the old price = £x
Percent increase. = 10%
Increment. = 10% of £x
= 10x/100
Now new price = £22
To determine the old price we have
x + 10x/100. = 22
We now multiply everything by 100 to make it a linear expression
100x + 10x = 2200
110x = 2200, therefore
x. = 2200/110
= £20
Therefore, the price before the increase. = £20.