Answer:
The number of boys are 64.
Step-by-step explanation:
We have,
The ratio of the boy to girl is 8:9.
Total number of girls are 72.
Let total boys are 8x and total girls are 9x.
According to the question,
[tex]9x=72\\\\x=8[/tex]
Since, number of boys are 8x. So,
[tex]B=8x=8\times 8=64[/tex]
So, the number of boys are 64.
Two tanks are interconnected. Tank A contains 60 grams of salt in 50 liters of water, and Tank B contains 80 grams of salt in 40 liters of water.
A solution of 2 gram/L flows into Tank A at a rate of 5 L/min, while a solution of 3 grams/L flows into Tank B at a rate of 7 L/min. The tanks are well mixed.
The tanks are connected, so 8 L/min flows from Tank A to Tank B, while 3 L/min flows from Tank B to Tank A. An additional 12 L/min drains from Tank B.
Letting x represent the grams of salt in Tank A, and y represent the grams of salt in Tank B, set up the system of differential equations for these two tanks.
Let a(t) and b(t) denote the amounts of salt in tanks A and B, respectively.
The volume of liquid in tanks A and B after t minutes are
A: 50 L + (5 L/min + 3 L/min - 8 L/min)t = 50 L
B: 40 L + (7 L/min + 8 L/min - 3 L/min - 12 L/min)t = 40 L
so the amount of solution in the tanks stays constant.
Salt flows into tank A at a rate of
(2 g/L)*(5 L/min) + (b(t)/40 g/L)*(3 L/min) = (10 + 3/40 b(t)) g/min
and out at a rate of
(a(t)/50 g/L)*(8 L/min) = 4/25 a(t) g/min
so the net flow rate is given by the differential equation
[tex]\dfrac{\mathrm da(t)}{\mathrm dt}=10+\dfrac{3b(t)}{40}-\dfrac{4a(t)}{25}[/tex]
We do the same for tank B: salt flows in at a rate of
(3 g/L)*(7 L/min) + (a(t)/50 g/L)*(8 L/min) = (21 + 4/25 a(t)) g/min
and out at a rate of
(b(t)/40 g/L)*(3 L/min + 12 L/min) = 3/8 b(t) g/min
and hence with a net rate of
[tex]\dfrac{\mathrm db(t)}{\mathrm dt}=21+\dfrac{4a(t)}{25}-\dfrac{3b(t)}8[/tex]
Replace a(t) and b(t) with x and y. Then the system is (in matrix form)
[tex]\dfrac{\mathrm d}{\mathrm dt}\begin{bmatrix}x\\y\end{bmatrix}=\dfrac1{200}\begin{bmatrix}-32&15\\32&-75\end{bmatrix}\begin{bmatrix}x\\y\end{bmatrix}+\begin{bmatrix}10\\21\end{bmatrix}[/tex]
with initial conditions x(0) = 60 g and y(0) = 80 g.
Sean tossed a coin off a bridge into the stream below. The path of the coin can be represented by the equation h = -16t2 + 72t + 100. How long will it take the coin to reach the stream?
Answer:
about 5.613 seconds
Step-by-step explanation:
Using the quadratic formula to find the value of t when h = 0, we have ...
at² +bt +c = 0
t = (-b±√(b²-4ac))/(2a)
t = (-72±√(72² -4(-16)(100)))/(2(-16))
t = (-72±√11584)/-32 = (9±√181)/4
Only the positive value of t is of interest.
The coin will hit the stream after (9+√181)/4 seconds ≈ 5.613 seconds.
A soda manufacturer claims that its Cherry Fizz soda has more carbonation than a competitor’s Cherry Eclipse soda. Bottles of both types of soda are opened, covered with a balloon, and then shaken. The diameter of each balloon is then measured. The mean balloon diameters are 2.3 inches for the Cherry Fizz soda and 2.1 inches for the Cherry Eclipse soda. A 90 percent confidence interval to estimate the difference in mean diameters, in inches, is (−0.8,1.2). Which of the following claims is supported by the interval?
Answer:
E) Because the interval contains 0, it is possible that there is no difference in mean carbonation levels.
Step-by-step explanation:
Hello!
The soda manufacturer claims that it's Cherry Fizz soda that has more carbonation than the competitor's Cherry Eclipse soda.
To test this claim they compared the carbonation by opening bottles of each soda, covered them with a balloon, and agitated the bottle to release the gas into the ballon. Later the balloon's diameter of each bottle of soda was measured.
Be the variables:
X₁: Diameter of a balloon filled with the gas of a Cherry Fizz soda bottle.
X₂: Diameter of a balloon filled with the gas of a Cherry Eclipse soda bottle.
X[bar]₁= 2.3 inches
X[bar]₂= 2.1 inches
The difference between the two means μ₁-μ₂ was estimated with a 90% CI, obtaining: [-0.8;1.2]inches
Usings 90% confidence level you can expect the interval [-0.8;1.2]inches to include the difference between the diameter of the balloons filled with the gas of the Cherry Fizz soda and the diameter of the balloons filled with the gas of the Cherry Eclipse soda.
The claims are:
A) Because 2.3 inches is larger than 2.1 inches, the manufacturer is correct, and Cherry Fizz has more carbonation.
INCORRECT, the given values are sample measures, you cannot reach any valid conclusions by simply comparing them.
B) Because the interval has more positive than negative values, Cherry Fizz has more carbonation.
INCORRECT, the confidence interval provides a range of values for the estimated parameter, it is equally probable that the parameter is closer to the lower bond, the upper bond, or in the middle of the interval.
C) Because 2.3 and 2.1 are very similar, there is no difference in the mean carbonation levels.
INCORRECT, same as in item A, you cannot reach any valid conclusion by just comparing the sample values, a propper hypothesis test is needed.
D) The interval cannot be interpreted because negative measurements are not possible.
INCORRECT, this interval vas made to estimate the difference between the two means, therefore if one value is less than the other it is possible to observe negative values.
If the CI was to estimate the value of the mean diameter of the balloons of one of the groups, then a negative measurement would be invalid.
E) Because the interval contains 0, there may be no difference in mean carbonation levels.
CORRECT
If you were to test the hypotheses
H₀: μ₁-μ₂=0
H₁: μ₁-μ₂≠0
Using a significance level, complementary to the confidence level used to construct the interval α: 0.1 you can decide whether or not the difference between population means are equal to zero or not.
If the interval contains the zero, then you do not reject the null hypotheses and there is no difference between the population means.
If the interval doesn't include the zero, then you reject the null hypothesis.
I hope this helps!
E) Because the interval contains 0, it is possible that there is no difference in mean carbonation levels.
What will be the answer?
The soda manufacturer claims that it's Cherry Fizz soda that has more carbonation than the competitor's Cherry Eclipse soda.
To test this claim they compared the carbonation by opening bottles of each soda, covered them with a balloon, and agitated the bottle to release the gas into the ballon. Later the balloon's diameter of each bottle of soda was measured.
Be the variables:
X₁: Diameter of a balloon filled with the gas of a Cherry Fizz soda bottle.
X₂: Diameter of a balloon filled with the gas of a Cherry Eclipse soda bottle.
X[bar]₁= 2.3 inches
X[bar]₂= 2.1 inches
The difference between the two means μ₁-μ₂ was estimated with a 90% CI, obtaining: [-0.8;1.2]inches
Usings 90% confidence level you can expect the interval [-0.8;1.2]inches to include the difference between the diameter of the balloons filled with the gas of the Cherry Fizz soda and the diameter of the balloons filled with the gas of the Cherry Eclipse soda.
The claims are:
A) Because 2.3 inches is larger than 2.1 inches, the manufacturer is correct, and Cherry Fizz has more carbonation.
INCORRECT, the given values are sample measures, you cannot reach any valid conclusions by simply comparing them.B) Because the interval has more positive than negative values, Cherry Fizz has more carbonation.
INCORRECT, the confidence interval provides a range of values for the estimated parameter, it is equally probable that the parameter is closer to the lower bond, the upper bond, or in the middle of the interval.C) Because 2.3 and 2.1 are very similar, there is no difference in the mean carbonation levels.
INCORRECT, same as in item A, you cannot reach any valid conclusion by just comparing the sample values, a propper hypothesis test is needed.D) The interval cannot be interpreted because negative measurements are not possible.
INCORRECT, this interval vas made to estimate the difference between the two means, therefore if one value is less than the other it is possible to observe negative values.If the CI was to estimate the value of the mean diameter of the balloons of one of the groups, then a negative measurement would be invalid.
E) Because the interval contains 0, there may be no difference in mean carbonation levels.
CORRECT If you were to test the hypothesesH₀: μ₁-μ₂=0H₁: μ₁-μ₂≠0Using a significance level, complementary to the confidence level used to construct the interval α: 0.1 you can decide whether or not the difference between population means are equal to zero or not.
If the interval contains the zero, then you do not reject the null hypotheses and there is no difference between the population means.
If the interval doesn't include the zero, then you reject the null hypothesis.
Thus the interval contains 0, it is possible that there is no difference in mean carbonation levels.
To know more about null Hypothesis follow
https://brainly.com/question/15980493
what is the equation to the following sentence?
Seven subtracted from two times a number is 13
Answer:
4x-7>13
add 7
4x>20
divide by 4
x>5
Step-by-step explanation:
Lacy enjoys running around the lake, and Paul enjoys running around the park. Lacy contends that she runs
farther around the lake than Paul runs around the park, and Paul contends the opposite.
To settle their debate, they find satellite images of the lake and the park and juxtapose them on a single
coordinate grid (shown below).
The perimeter of the lake is m
Round the final answer to the nearest meter. Do not round intermediate calculations.
The perimeter of the park is m
Round the final answer to the nearest meter. Do not round intermediate calculations.
Who should win the debate?
Answer:
The perimeter of the lake is 314m. The perimeter of the park is 339 m. Paul should win the debate.
Step-by-step explanation:
what is
a=
b=
c=
d=
e=
Answer:Not enough info
Step-by-step explanation: need more
if i'm 18 and my sister is 19, how much younger am I than she is?
Answer:
one year
Step-by-step explanation:
What is the sum of 6 x 12?
Answer:
72
Step-by-step explanation:
because 6 x 10 is 60 so 6 x 2 is 12, so 12 + 60 is 72.
The average hourly wage for a high school student in Illinois is $8.25 per hour with a standard deviation of $.25. Assume hourly wages vary normally.
A) Determine the margin of error for this scenario.
B) For the previous question you just answered, construct a 95% confidence interval for the hourly wage for a high school student.
C) For the 95% confidence interval you just constructed, does an hourly wage of $9.15 fall within that acceptable range?
Answer:
Step-by-step explanation:
Hello!
The variable of interest is
X: hourly wage of a high school student
X~N(μ;σ²)
X[bar]= $8.25
σ= $0.25
For a 95% CI for the average hourly wage for 1 high school student:
For this exercise you have to consider the sample size n=1
a) The margin of error of the CI is calculated as:
d= [tex]Z_{1-\alpha /2}[/tex] * σ
1-α: 0.95 ⇒ α:0.05
1-α/2:0.975
[tex]Z_{1-\alpha /2}= Z_{0.975}= 1.96[/tex]
d= 1.96 * 0.25= 0.49
b)
The formula for the interval is
X[bar] ± [tex]Z_{1-\alpha /2}[/tex] * σ
[8.25 ± 0.49]
[7.76; 8.74]
With a 95% you'd expect the interval $[7.76; 8.74] to include the average hourly wage of one high school student in Illinois.
c)
Te calculated interval is $ [7.76; 8.74] the value $9.15 does nor fall within that acceptable range.
I hope this helps!
What is 1 2/3 - 2 1/3?
Step-by-step explanation:
First it will be easer if you turn both sides into improper fractions
5/3-7/3
Now do 5-7
5-7=-2
The bottom of the fraction stays the same
-2/3 is your answer.
What’s the correct answer for this question?
Answer:
D
Step-by-step explanation:
Izan can use the slope formula to show that the slope of KL and MN are equal.
The plans for a home renovation include a new window. The homeowner picked a window shaped like the one shown. Identify the polygon and classify it as regular or irregular.
Answer:
Octagon regular.
Step-by-step explanation:
This shape has 8 sides to it is an octagon. A octagon irregular doesn't have equal sides while this one does. The best way to tell is if it looks like a stop sign which are octagon regular.
a circle with area 36pi has a sector with a central angle of 48°. what is the area of the sector?
Answer:4.8π
Step-by-step explanation:
Φ=48°
Area of circle=36π
Area of circle=π x r^2
36π=πr^2
Dividing both sides by π we get
r^2=36π/π
r^2=36
Take them square root of both sides
√(r^2)=√(36)
r=6
Area of sector=Φ/360 x π x r x r
Area of sector=48/360 x π x 6 x 6
Area of sector=(48xπx6x6)/360
Area of sector=1728π/360
Area of sector=4.8π
What’s the correct answer?
Answer:
B.
Step-by-step explanation:
Answer:b
Step-by-step explanation:you need to add both
what’s the gcf of x^2 and 5x
Answer:
the GCF of x^2 and 5x is x
Find the prime factors of each term in order to find the greatest common factor (GCF).
A North American company manufactures rivets for use in car production. A sample of forty rivets from the production line had mean 6.803 and standard deviation 0.275 (both in 1/100 of an inch). On communicating these results to the company headquarters in Europe, a request is made for the summary statistics to be converted into millimeters. Given that one inch is 2.538 centimeters, find the mean and standard deviation of the sample in millimeters. What is the mean in millimeters
Answer:
Mean = 1.73 mm
Standard deviation = 0.0698 mm
Step-by-step explanation:
Given:
Sample size, n = 40
Mean, u = 6.803
Standard deviation = 0.275
a) Given that one inch is 2.538 centimeters, to find the mean in millimeters we have:
[tex] 6.803 * \frac{1}{100} [/tex]
Converting to cm, we have:
[tex] 6.803 * \frac{1}{100} * 2.538 = 0.173 cm[/tex]
Converting to mm, we know 1cm = 10 mm,
0.173 * 10 = 1.73 mm
b) Given that one inch is 2.538 centimeters, to find the standard deviation in millimeters we have:
[tex] 0.275 * \frac{1}{100} [/tex]
Converting to cm, we have:
[tex] 0.275 * \frac{1}{100} * 2.538 = 0.00698 cm[/tex]
Converting to mm, we know 1cm = 10 mm,
0.00698 * 10 = 0.0698mm
In this exercise we have to use the knowledge of statistics to calculate the car production, so we have to:
Mean: [tex]1.73mm[/tex]Standard deviation: [tex]0.0698 mm[/tex]Given the following information, we have:
Sample size n = 40 Mean u = 6.803 Standard deviation = 0.275A) Find the convertion to the mean in milimeters, will be:
[tex]6.803*(1/100)*2.538=0.173 cm\\=1.73 mm[/tex]
B) Find the convertion to the stardard deviation in milimeters, will be:
[tex]0.275*(1/100)*2.538=0.00698\\=0.0698 mm[/tex]
See more about statistics at brainly.com/question/10951564
IL GIVE YOU BRAINLIST !! * have to get it right * An equation for the line graphed is
Answer:
y = 3/2x+3
Step-by-step explanation:
The y intercept is 3. That is where it crosses the y axis
The slope is
m= (y2-y1)/(x2-x1) and we have points(0,3) and (-2,0)
= (0-3)/(-2,0)
=-3/-2
=3/2
Using the slope intercept form of a line
y = mx +b where m is the slope and b is the y intercept
y = 3/2x+3
What is the measure of its remote interior angle?
Answer:<1=126° <2=54°
Step-by-step explanation:
sum of angles in a =180°
<2+90+36=180
<2+126=180
Collect like terms
<2=180-126
<2=54°
<2 and <1 are supplementary angles therefore their sum is equal to 180
<2 + <1=180
54 + <1=180
Collect like terms
<1=180-54
<1=126
change 5 out of 19 to a percentage
Answer:
26.3%
Step-by-step explanation:
5 is divided by 19
That answer is then multiplied by 100.
You may round your answer to the nearest whole number.
Plane P cuts sphere o in a circle that has diameter
20. If the diameter of the sphere is 30, how far is the
plane from O?
Answer:
5√5 ≈ 11.18 units
Step-by-step explanation:
The Pythagorean theorem can be used to find the unknown leg of a triangle with hypotenuse 15 and one leg 10:
d = √(15^2 -10^2) = 5√(3^2 -2^2) = 5√5
The plane is 5√5 units from the center of the sphere.
0.6666666……… as a percentage
Answer:
2/3
Step-by-step explanation:
Answer: 66.66%
Step-by-step explanation: You multiply 0.66666... by 100 and that gives you 66.66
The edges of a cube increase at a rate of 2 cm divided by s. How fast is the volume changing when the length of each edge is 40 cm? Write an equation relating the volume of a cube, V, and an edge of the cube, a. nothing Differentiate both sides of the equation with respect to t. StartFraction dV Over dt EndFraction equals(nothing )StartFraction da Over dt EndFraction (Type an expression using a as the variable.) The rate of change of the volume is nothing cm cubed divided by sec. (Simplify your answer.)
Answer:
Step-by-step explanation:
Let the edge of the cube be a .
Given
[tex]\frac{da}{dt} = 2 cm/s[/tex]
Volume V = a³
[tex]\frac{dV}{dt} = 3a^ 2\frac{da}{dt}[/tex]
= 3a² x 2
= 6a²
If a = 40 cm
[tex]\frac{dV}{dt} = 6 \times 40\times40[/tex]
= 9600 cm³/s .
If you put all the sunflowers together end to end, what would be the total length of all the sunflowers?
Answer:
7 1\68
Step-by-step explanation:
all i did was look up a fraction calculator
calculator soup is the one i used :)
Jared has earned 23% of the $52 he needs to buy a new jacket. Find 23% of $52.
Which expression can you use to find 23% of 52? ..
23% of $52 is $..
An easy way to check your answer is to use the friendly and divide 52 by to get ..
Answer:
Which expression can you use to find 23% of 52? "0.23 x 52"
23% of $52 is $. "11.96"
An easy way to check your answer is to use the friendly 25% and divide 52 by 4 to get 13.
Step-by-step explanation:
just did it good luck everyone
23% of $52 is $11.96.
In order to determine the value of 23% of $52, we would multiply 23% by $52. Multiplication is a basic mathematical operation that entails adding a certain number by itself a certain number of times. The sign used to represent multiplication is ×.
23% x 52
= 0.23 x 52 = $11.96
To learn more, please check: https://brainly.com/question/92258
a number rounded to the nearest hundred thousand is 400,000 the same number rounded to the nearest ten thousand is 350,000 what could be the number
Answer:350000
Step-by-step explanation:
The number is 350000
350000 rounded to the nearest hundred thousand is 400000
350000 rounded to the nearest ten thousand is 350000
What’s the correct answer for this?
Answer:
(2,7)
Step-by-step explanation:
In the attached file
a candlemaker prices one set of scented candles at $10
y=10x
x= how many candles
Erin built a wooden box to hold hay on her farm. The box is 3 m long, 1 m wide, and 1 m high. Hay costs $14 per cubic meter.
Answer:
It will cost 42 to completely fill the box with hay.
have a good day <3
A building is 864 inches (in) tall. How many feet (ft) is this?
Answer:
72 ft.
Step-by-step explanation:
12 inches = 1 foot
Answer:
72 feet
Step-by-step explanation:
math calculator
Which expression can be used to find the area of the rectangle shown on the coordinate plane 6×7 7×7 8×7 8×8
Answer:that’s a lot of numbers.
Step-by-step explanation:
