The rate at which the surface area is changing when r = 6cm is 96[tex]cm^{2}[/tex]/min.
Surface area of SphereThe surface area of a sphere with radius r is given by4π[tex]r^{2}[/tex]
Given;
S = surface area at time t, and r = radius at time t
radius of a spherical ball is increasing at a rate of 2 cm/min
radius: 6cm
Area of a sphere is A = 4π[tex]r^{2}[/tex]
Step 1: Differentiate area of a spherical ball
A = 4π[tex]r^{2}[/tex]
[tex]\frac{dA}{dt}[/tex] =[tex]\frac{d}{dt}[/tex](4π[tex]r^{2}[/tex])
=4π [tex]\frac{d}{dt}[/tex]([tex]r^{2}[/tex])
=4π2r [tex]\frac{dr}{dt}[/tex]
[tex]\frac{dA}{dt}[/tex] = 8πr
since we have that dr/dt = 2 cm/min. Thus, the radius of the ball is 6cm, we have;
[tex]\frac{dA}{dt}[/tex]= 8π(6)(2) =96π
So, the rate at which the surface area is changing when r = 6cm is 96[tex]cm^{2}[/tex]/min.
Note that measuring area unit is cm2/min
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Find the circumference and the area of a circle with diameter 7 cm.
The circumference of the circle is 21.98cm and the area of the circle is 38.465 square cm.
Circumference of the circle:
The Circumference (also known as) perimeter of circle = 2πR
where,
R is the radius of the circle
π is the mathematical constant with an approximate value is 3.14.
Area of circle:
The formula to find the area of the circle is;
A = πr²
Where r represents the radius of the circle.
Given,
The diameter of the circle is 7 cm.
Here we need to find the circumference and the area of a circle.
Here we have the value of diameter, in order to find the circumference we have to find the value of radius that can be derived by dividing the diameter by 2.
So, the radius is
=> 7/2 = 3.5
Now the circumference of the circle is calculated as,
C = 2 x π x 3.5
When the value of π = 3.14
Therefore, the circumference of the given circle is,
=> C = 2 x 3.14 x 3.5
=> C = 21.98
Now, the area of the circle is,
=> A = π x (3.5)²
=> A = 3.14 x 12.25
=> 38.465
Therefore, the area of the circle is 38.465 square cm.
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Construct a 98% confidence interval based on the data. Assume the variable is normally distributed
The 98% confidence interval limits are given by 1.6 < μ < 33.7.
What is the confidence interval in statistics?
A confidence interval is the mean of your estimate plus and minus its variation. Within a certain confidence level, this is the range of values you expect your estimate to fall between if you redo your test. In statistics, confidence is another word for probability.
Given data: 10, 32, 24, 0, 5, 27, 5, 50, 6.
Sample mean = ∑x/n = 159/9 = 17.66
Sample variance = s² = ∑(x - sample mean)²/n-1
= 2206/8
= 275.75
Sample standard deviation = s = [tex]\sqrt{s^2}[/tex]
= [tex]\sqrt{275.75}[/tex]
= 16.60
Significance level = α = 1 - 0.98 = 0.02
Degree of freedom (d.f.) = n - 1 = 9 - 1 = 8
Critical value = [tex]t_{{\frac{\alpha}{2}},d.f}[/tex]
= 2.896
Margin of error = E = critical value * [tex]\frac{s}{\sqrt{n} }[/tex]
= 16.03
Limits of 98% confidence level are given by:
Lower limit = sample mean - E = 17.66 - 16.03 ≈ 1.6
Upper limit = sample mean + E = 17.66 + 16.03 ≈ 33.7.
Hence, the 98% confidence interval limits are given by 1.6 < μ < 33.7.
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Find the quotient.
2.4)7.68
Answer:0.3125
Step-by-step explanation:
none sry
Movies at the rental store are $3.75 each. Snacks and drinks are $1.89 each. Round each amount to the nearest dollar to estimate the cost to rent 3 movies and buy popcorn, a soda, and a candy bar.
Answer: List all of the solutions.
3.75
=
1.89
=
dollar
=
3
=
Step-by-step explanation:
Una torre de 50 pies está a la orilla de un río. El ángulo de elevación entre la orilla opuesta y la punta de la torre es de 37°. ¿Qué anchura tiene el río?
Usando una relación trigonometrica veremos que la anchura del rio es 66.4 pies.
¿Como encontrar la anchura del rio?
Podemos ver la situación como si trabajaramos con un triangulo rectangulo, donde la torre de 50 pies es un cateto y la anchura del rio es el otro cateto. (la imagen de este triangulo se puede ver en la imagen al final)
Usando la relacion:
tan(a) = (cateto opuesto)/(cateto adjacente)
Podemos escribir:
tan(37°) = 50ft/x
Resolviendo para x, la anchura del rio:
x = 50ft/tan(37°) =66.4 ft
El rio tiene un ancho de 66.4 pies.
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(MARKING BRAINLIEST) Maggie and Katie go out to dinner there a bill comes to $64.50 they are required to pay 8.5% sales tax what is the total amount Maggie and Katie have to pay ?
Answer:
$69.98
Step-by-step explanation:
8.5% of 64.50 is around 5.48 or to be exact, 5.4825 which there are no more dollar denominations beyond the hundredth place so it would be 5.48. 64.50+5.48 is $69.98.
Answer:
$69.98
Step-by-step explanation:
It is percent increase.
So, 100% + 8.5% = 108.5% which is 1.085.
64.50 × 1.085 = 69.9825
we need to round to 2 decimal places
$69.98
Find the values of x and y.
The required angles of x and y are x = 65° and y = 25°
Given is a triangle which is right angled
Thus the sum of the right angled triangle is 180 degrees
So we will write
y° + x + 90 = 180 [ angle sum property of the triangle ]
90 + x + y = 180
let the above equation be considered as equation 1
Since two sides are equal
thus the other angle will also be x°
Also the angle adjacent to 40° can be found out by linear angle property
thus according to this :
x + x + ( 90 - 40 ) = 180 °
2x + 50 = 180
thus subtracting 50 on both sides we get
2x = 130
x = 65°
Thus by equation 1
we can rewrite it as
y + x + 90 = 180
65 + 90 + y = 180
155 + y = 180
this implies y = 180 - 155
y = 25°
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Which of the three triangles below can be proven congruent by SSS or SAS
Answer:
The answer for number 7 is A
Step-by-step explanation:
I hope this helps
Define rational number in your own words.
Answer:A rational number is a number thats a quotient or fraction
Step-by-step explanation:
4\6 would be a rational number 8 over 4 as well.
2 1/7:15a=5/14:0.8. solve
The value of a from the equation is a = 0.32
What is an Equation?
Equations are mathematical statements with two algebraic expressions flanking the equals (=) sign on either side.
It demonstrates the equality of the relationship between the expressions printed on the left and right sides.
Coefficients, variables, operators, constants, terms, expressions, and the equal to sign are some of the components of an equation. The "=" sign and terms on both sides must always be present when writing an equation.
Given data ,
Let the equation be 2 1/7 : 15a = 5/14 : 0.8
Now , on simplifying the equation , we get
15/7 : 15a = 5/14 : 0.8
Multiply by 14 on both sides of the equation , we get
( 15 x 2 ) : 15a = 5 : 0.8
30 : 15a = 5 : 0.8
So , on simplifying the equation , we get
30 / 15a = 5 / 0.8
Divide by 5 on both sides , we get
6 / 15a = 1 / 0.8
Multiply by 0.8 on both sides of the equation , we get
15a = 6 x 0.8
15a = 4.8
Divide by 15 on both sides , we get
a = 4.8 / 15
a = 0.32
Therefore , the value of a = 0.32 or a = 8 / 25
Hence , the value of a in the equation is a = 0.32
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Write an equation for the trend line shown on the scatter plot. ASP
Answer:
y=5x+15
Step-by-step explanation:
the equation of a line is y=mx+b where b is the y-intercept and m is the slope.
if you look at the graph you will see that your line intecpts the y axes at b=15 or that would be your y value where the line touches the edge.
now you just have to find your slope. slope is y/x or rise/run
so by looking at the graph at where our line touches the corner of a square. we just need to find 2 of those. we can use (0,15) and (1,20) the distance from 15 to 20 is 5 so that is our rise or change in y. the distance from 0 to 1 is 1 so that is our change in x or run. now just put rise over run so 5/1 which is just 5.
lastly we fill out our equation y=mx+b
our slop m is 5 and our y-intercept b is 15 so y=5x+15
Find the value of x.
(x + 8)
Answer:
52°
Step-by-step explanation:
This is an equilateral triangle. Therefore all the sides and angles are equal to each other.
We know that,
the sum of the interior angles in a triangle is 180° and in equilateral triangles each angle measured 60° ( 180°/3 ).
Accordingly,
x + 8 = 60
Subtract 8 from both sides.
x = 60 - 8
x = 52°
18. MULTIPLE CHOICE
(Lesson 2-6)
(A) X=-4
B) X= 4
Ox=8
(D) X = 20
Solve
3
x + 4
=
2
X-4
Answer:
Step-by-step explanation:
solving 3x+4=2x-4
now 3x-2x=-4-4
⇒ x=-8
(c) x=8 here you have given it as O thank you
For each equation, determine whether it represents a direct variation, an inverse variation, or neither.
Find the constant of variation when one exists and write it in simplest form.
The equation 4y = -x is a direct variation and k = - 1 / 4.
The equation 3x = 2y - 7 is neither a direct variation nor a inverse variation.
How to solve direct and inverse equation?Direct variation describes a simple relationship between two variables . We say y varies directly to x when it is represented as follows:
y = kx
where
k = constant of proportionalityTherefore,
4y = - x
divide both sides of the equation by 4
4y / 4 = -x / 4
[tex]y =- \frac{x}{4}[/tex]
Therefore, the equation is direct variation and the value of k is - 1 / 4.
For two quantities with inverse variation, as one quantity increases, the other quantity decreases. Inverse variation is represented as follows:
y = k / x
Therefore, 3x = 2y - 7 is neither an inverse nor a direct variation.
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1. Write an addition problem that has a sum of -4 a. The two addends have the same sign. b. The two addends have different signs.
Answer:
a. -1 + (-3)
b. -9 + 5
Step-by-step explanation:
the sum of two numbers = -4
a.
two addends have the same sign
Since the sum is negative, then both addends must be negative.
Answer: -1 + (-3) =
b.
two addends have different signs
One addend is positive, and one addend is negative. Since the sum is negative, then the addend with the greater absolute value must be negative.
Answer: -9 + 5 =
The frequency table gives information about the numbers of mice in some nests
answer:
we need the table.
Suppose that y varies directly with x, and y=4 when x = 10.
(a) Write a direct variation equation that relates and y Equation: y =
Answer:
y = 0.4x
Step-by-step explanation:
given that y varies directly with x then the equation relating them is
y = kx ← k is the constant of variation
to find k use the condition y = 4 when x = 10 , then
4 = 10k ( divide both sides by 10 )
[tex]\frac{4}{10}[/tex] = k , that is
k = 0.4
y = 0.4x ← equation of variation
HELP!!WILL MARK BRAINILIEST!!
Which graph shows a proportional relationship between x and y?
Graph C appears to show a proportional relationship between x and y. Because it is a straight line across the origin.
What is a proportional relationship?
Relationships between two variables where their ratios are equal are known as proportional relationships. The fact that one variable is always a constant value multiplied by the other in a proportionate connection is another way to conceive of them.A line graph is a particular sort of graph in which the connecting segments of straight lines represent the data points. A straight line is made up of many points connected at each end.
A straight line with a beginning point of represents a proportionate relationship on a graph (0, 0). By computing a second point and then connecting the two with a straight line, the graph is produced.
As a result, graph C seems to indicate that x and y are proportionate. due to the fact that it crosses the origin directly.
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write an equation in slope-intercept form the table. help fast please
x: -4, 0, 4, 8, 12
y: 5, 6, 7, 8, 9
The linear equation in the table is written as:
y = (1/4)*x + 6
How to write the linear equation?The linear equation in slope-intercept form is written as:
y = m*x+ b
Where m is the slope and b is the y-intercept.
We know that if a line passes through two points (x₁, y₁) and (x₂, y₂), then the slope is:
m = (y₂ - y₁)/(x₂ - x₁)
Here we can use the first two points on the table:
(-4, 5) and (0, 6), so the slope is:
m = (6 - 5)/(0 + 4) = 1/4
And because of the point (0, 6) we know that the y-intercept is 6, then the line is:
y = (1/4)*x + 6
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help me 10 pnts thanks so much
The expression 3.2^2 - 1 and 10 - 0.33 * 2 should be joined by less than to form an inequality
What is inequality?Inequality refers to a way of representing relationships between variables at the left hand side of equation to the variables to the right hand side of an equation.
The signs used in inequality are of 4 types namely
less thangreater thanless than or equal togreater than or equal toThe given expression is solved as follows
3.2^2 - 1
= 10.24 - 1
= 9.24
10 - 0.33 * 2
= 10 - 0.66
= 9.34
The two expressions can be joined as below
9.24 < 9.34
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Which point could be used to find f(2)?
A
B
C
D
Point A will represent the input-output values of the function.
What is number line ?
Number line is virtual representation of numbers along with coordinates axis with number equally spaced with equal number of interval.
In the graph of y = f(x),
For every x-value (input value), value of the function is the y-value (output value).
For the input value x = 2,
Output value of the function will be,
y = f(2)
Therefore, point A will represent the input-output values of the function.
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According to the graph provided, the weight for someone who is 1.4 meters tall is predicted to be close to kilograms
According to the scatterplot (graph) provided, the weight for someone who is 1.4 meters tall is predicted to be 34.8 kilograms.
What is a scatterplot?A scatterplot is also referred to as scatter diagram, scattergram, or scatter chart and it can be defined as a type of graph which is used for the graphical representation of the values of two (2) variables, with the resulting points showing any association between the data set.
For this exercise, the height (M) was plotted on the x-axis of the scatterplot (graph) while the weight (in kg) would be plotted on the y-axis of the scatterplot (graph).
From the scatterplot which models the relationship between the height (M) and weight (in kg) of a person, an equation for the line of best fit is given by:
Weight, kg = -114.3 + 106.5M
When M = 1.4 meters, we have the following weight:
Weight, kg = -114.3 + 106.5(1.4)
Weight, kg = -114.3 + 149.1
Weight, kg = 34.8 kg.
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Complete Question:
According to the graph provided, the weight for someone who is 1.5 meters tall is predicted to be close to ____ kilograms.
what is the expected value of x? where x/p equals 0/.15, 4/.05, 8/.25, 12/.05, 16/.5
The expected value of x is 10.8
How calculate the expected value of x?Expected value is defined as the predicted value of a variable, calculated as the sum of all possible values each multiplied by the probability of its occurrence.
Given :
x| 0 4 8 12 16
p| 0.15 0.05 0.25 0.05 0.5
The expected value of x, E(x) =Σ xp
E(x) = (0×0.15) + (4×0.05) + (8×0.25) + (12×0.05) + (16×0.5)
E(x) = 0 + 0.2 + 2 + 0.6 + 8
E(x) = 10.8
Therefore, the expected value of x is 10.8
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(MARKING BRAINLIEST) Sam works as a salesman and earns 5.5% commission on everything he sells if Sam sells a television for $1200 how much commission will he earn ?
Answer:
$66
Explanation:
Sam earns a 5.5% commission on everything he sells. He sells a television for $1200. What is 5.5% of $1200?
Convert 5.5% to decimal form: 0.055. Now, multiply 1200 by 0.055.
Sam will earn $66 because 5.5% of 1200 is 66.
Which represents the solutions of the graphed system of equations y=x2+2x-3 and y=x-1?
Answer:
second option
Step-by-step explanation:
the solution to the system of equations is at the points of intersection of the two graphs.
the graphs intersect at (- 2, - 3 ) and (1, 0 ) , then
the solutions are (- 2, - 3 ) and (1, 0 )
Is this the right answer?
Answer:
Step-by-step explanation:
Yeah you have the correct answer.
In the original line you solve for y where the slope is given -3.
Then it is up to you but I like using the point slope formula so I'll plug in the values and the result is the same as the picture.
y-y=m(x-x)
y-(-6)=-3(x-1)
PLEASE HELP!! PLEASE I WILL GIVE YOU BRAINLIST!! PLEASE ASAP :)
LMNP is rotated 180° clockwise about the origin.
What are the coordinates of M' ?
Answer:
M'(-3, -4)
Step-by-step explanation:
the coordinate rules for a rotation of 180 degrees is (x, y) --> (-x, -y)
Basically, you just change both values (x and y) of M to negative. Then bam, u got the coordinates for M'
write 10 forms for 1 over 8 as you can think of, be creative and use positive and negative powers or other forms of number.
The 10 forms 1/8 can be written is as follows;
1/81 ÷ 81/2³1/√64[tex]{8}^{ - 1} [/tex][tex]{√64}^{ - 1} [/tex]1 : 8[tex]{2}^{ - 3} [/tex]2/164 : 32How to write 1/8 in different forms?A fraction refers to a number which consists of a numerator and a denominator.
A numerator is the upper value of a fraction.
A denominator is the lower value of a fraction.
1 over 8 can be written in the following ways;
1/8
1 ÷ 8
1/2³
= 1 / 2×2×2
= 1/8
1/√64
= 1/8
[tex]{8}^{ - 1} [/tex]
= 1/8
1 : 8
= 1/8
[tex]{√64}^{ - 1} [/tex]
= 1/√64
= 1/8
[tex]{2}^{ - 3} [/tex]
= 1/2³
= 1/8
2/16
= 1/8
4 : 32
= 4/32
= 1/8
In conclusion, 1/8 can be written in different forms including using square root and ratios.
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Solve the Inequality and graph the solution set.
-8-8(2x-4)>-5(4x-5)-21
Answer:
x > -5
Make a number line. Put a circle on the number line at -5 and then darken an arrow on the number line going to the right of -5
Step-by-step explanation:
-8-8(2x-4) > -5(4x -5) -21 Distribute the -8 and -5
-8 - 16x + 32 > -20x +25 -21 Combine like terms
-16x + 24 > -20x +4 Add 20x to both sides
4x + 24 > 4 Subtract 24 from both sides
4x > -20 Divide both sides by 4
x > -5
An engineer has designed a valve that will regulate water pressure on an automobile engine. The valve was tested on 200 engines and the mean pressure was 5.8 pounds/square inch (psi). Assume the population standard deviation is 1.0. The engineer designed the valve such that it would produce a mean pressure of 6.0 psi. It is believed that the valve does not perform to the specifications. A level of significance of 0.02 will be used. Find the value of the test statistic. Round your answer to two decimal places.
The value of the test statistic when the engineer has designed a valve is -2.83.
How to calculate the test statistic?From the information, the following can be deduced:
Sample mean = 5.8
Population mean = 6.0
Population standard deviation = 1
Significance level = 0.02
(Sample mean - Population mean) /(Standard Deviation / ✓200)
= (5.8 - 6.0) / (1 / ✓200)
= -0.2 ✓200
= -2.83
The value is -2.83.
It's important to note that the test statistic is the z value. This will be:
=
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