Answer: A = 4πr^2
Explanation:
The formula for calculating the radius of a sphere is
r = √A/4π
To solve for A, the first step is to square both sides of the equation. We have
r^2 = (√A/4π)^2
r^2 = A/4π
The next step is to cross multiply. It becomes
A = r^2 * 4π
A = 4πr^2
A small lawnmower company produced 1,500 lawnmowers in 2008. In an effort to determine how maintenance-free these units were, the company decided to conduct a multiyear study of the 2008 lawnmowers. A sample of 200 owners of these lawnmowers was drawn randomly from company records and contacted. The owners were given an 800 number and asked to call the company when the first major repair was required for the lawnmowers. Owners who no longer used the lawnmower to cut their grass were disqualified. After many years, 183 of the owners had reported. The other 17 disqualified themselves. The average number of years until the first major repair was 3.3 for the 183 owners reporting. It is believed that the population standard deviation was 1.47 years. If the company wants to advertise an average number of years of repair-free lawn mowing for this lawnmower, what is the point estimate? Construct a 95% confidence interval for the average number of years until the first major repair.
Answer:
The 95% confidence interval for the average number of years until the first major repair is (3.1, 3.5).
Step-by-step explanation:
The (1 - α)% confidence interval for the average using the finite correction factor is:
\(CI=\bar x\pm z_{\alpha/2}\cdot\frac{\sigma}{\sqrt{n}}\cdot\sqrt{\frac{N-n}{N-1}}\)
The information provided is:
\(N=1500\\n=183\\\sigma=1.47\\\bar x=3.3\)
The critical value of z for 95% confidence level is,
z = 1.96
Compute the 95% confidence interval for the average number of years until the first major repair as follows:
\(CI=\bar x\pm z_{\alpha/2}\cdot\frac{\sigma}{\sqrt{n}}\cdot\sqrt{\frac{N-n}{N-1}}\)
\(=3.3\pm 1.96\times\frac{1.47}{\sqrt{183}}\times\sqrt{\frac{1500-183}{1500-1}}\\\\=3.3\pm 0.19964\\\\=(3.10036, 3.49964)\\\\\approx (3.1, 3.5)\)
Thus, the 95% confidence interval for the average number of years until the first major repair is (3.1, 3.5).
Adam was collecting bonus points toward a prize. The first and second weeks he earned
15 points each. The third and fourth weeks he earned 21 points each. When he turned in
his points on the last week, he found that 5 of the points weren't valid. How many points
did he receive credit for altogether?
Answer:
67 pointsStep-by-step explanation:
\((15 + 15) + (21 + 21) + - 5 \\ 30 + 42 - 5 \\ 67\)
I hope that is useful for you :)
What is the least common denominator of the rational expressions below?
1/x^2 - 4/3x^2+15x
Answer:
The LCD is 3x²
The other two denominators can be factors of 3x²
Step-by-step explanation:
To get the equivalent fractions, divide the original denominator into the LCD, then multiply the original numerator by the quotient.
For the first term: 1/x²
3x² ÷ x² = 3 3×1=3 The equivalent is 3/3x²
Second term: Leave it as it is.
For the third term: 15x
The implied denominator is 1
3x² ÷ 1 = 3x² 3x² × 15 = 135x²
The equivalent is 135x²/3x²
To check the validity, substitute a value for x and calculate the numbers.
For example let x = 3
The original expression becomes
1/3² + 4/3(3²) - 15(3)
1/9 + 4/27 - 45
With the LCD it is
3/27 + 4/27 - 1215/27
Answer:
3x^2(x+5)
Step-by-step explanation:
hope this helps
What are the domain and range of the function f(x)=-x+3-2? domain: -3 -2 domain: -3 -3 range: y<-2 domain: x>-3 range:y>-2
For given function function f(x)=-x+3-2, the domain is x > -3 and the range is y ≤ 2. So, correct option is D.
The function f(x)=-x+3-2 is a linear function in the form y=mx+b, where m is the slope and b is the y-intercept. In this case, the slope is -1 and the y-intercept is 1. Therefore, the graph of the function is a straight line that intersects the y-axis at (0,1) and has a slope of -1, meaning that it decreases by 1 for every 1 unit increase in x.
The domain of the function is the set of all possible values of x for which the function is defined. Since there are no restrictions on the value of x in the equation f(x)=-x+3-2, the domain is all real numbers, or (-∞, ∞).
The range of the function is the set of all possible values of y that the function can output. In this case, the lowest possible value of y occurs when x approaches positive infinity, and the highest possible value of y occurs when x approaches negative infinity. Therefore, the range is all real numbers less than or equal to 2, or y ≤ 2.
So, the domain is x ∈ (-∞, ∞) and the range is y ≤ 2. Alternatively, the domain can also be expressed as x > -3, since that is the minimum value of x at which the function is defined.
Correct option is D.
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Complete question is:
What are the domain and range of the function f(x)=-x+3-2?
A) domain: -3 -2
B) domain: -3 -3 range: y<-2
C) domain: x>-3 range:y>-2
D) domain : x>-3 range: y ≤ 2
Write a fraction that is equivalent to 3/5 that has a denominator of 20.
5
15
20
20
12
12
20
3
20
Answer:
12/20
Step-by-step explanation:
\(\displaystyle \frac{3}{5}=\frac{3}{5}\cdot\frac{4}{4}=\frac{12}{20}\)
The answer is:
12/20In-depth-explanation:
The denominator of 3/5 is 5. To get from 5 to 20, we multiply it by 4.
We need to multiply both the numerator and the denominator by 4, so we do this:
\(\sf{\dfrac{3\times4}{5\times4}}\)
\(\sf{\dfrac{12}{20}}\)
Hence, the answer is 12/20.I need to find how much Julia will pay so I have to solve for 3x+5y=50X+5y=31 but if I do that The answer that it gives me I can’t plug it in because is in ( 19/2,43/10) but I need Ane specific answer how can I solve for this ?
The first step is to find the values of x and y. From the information given,
x is the cost of an adult ticket and y is the cost of a child ticket. The system of equations is shown below
3x + 5y = 50
x + 5y = 31
From the second equation,
x = 31 - 5y
We would substitute x = 31 - 5y into 3x + 5y = 50. We have
3(31 - 5y) + 5y = 50
By expanding the parentheses, we have
93 - 15y + 5y = 50
- 15y + 5y = 50 - 93
- 10y = - 43
Dividing both sides of the equation by - 10,
- 10y/- 10 = - 43/- 10
y = 4.3
Substituting y = 4.3 into x = 31 - 5y, we have
x = 31 - 5 * 4.3 = 31 - 21.5
x = 9.5
If an adult ticket costs $9.5, then the cost of 4 adult tickets is
4 x 9.5 = $38
sin(x)-cos(x)/sin²(x)-cos²(x) = 1
The prove of the given trigonometric function is given below.
The given trigonometric function is,
(sin⁴(x) - cos⁴(x))/(sin²(x) - cos²(x))
Now proceed left hand side of the given expression:
We can write the expression as,
⇒[(sin²(x))² - (cos²(x))²]/(sin²(x) - cos²(x))
Since we know that ,
Algebraic identity:
a² - b² = (a-b)(a+b)
Therefore the above expression be
⇒(sin²(x) - cos²(x))(sin²(x) + cos²(x))/(sin²(x) - cos²(x))
⇒(sin²(x) + cos²(x))
Since we know that,
Trigonometric Identities come in handy when trigonometric functions are used in an expression or equation. Trigonometric identities hold for all values of variables on both sides of an equation. Geometrically, these identities include one or more trigonometric functions (such as sine, cosine, and tangent).
Then,
sin²(x) + cos²(x)² = 1 is an trigonometric identity
Hence,
(sin⁴(x) - cos⁴(x))/(sin²(x) - cos²(x)) = 1
Hence proved.
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Can someone help me solve this math problem?
what number is the opposite of 13/5?
Answer:
-13/-5 is the opposite of 13/5. Hope this helps :)
May someone help with this? Solve using the order of operations.
9/6 - 4(2/3 - 7/6)²
By algebraic handling, the expression 9 / 6 - 4 · (2 / 3 - 7 / 6)² is equivalent to the expression 1 / 2.
How to simplify an algebraic expression that involves power and rational expressions
In this problem we must simplify an expressions involving powers and rational numbers by algebra definitions and theorems:
9 / 6 - 4 · (2 / 3 - 7 / 6)² Given
9 / 6 - 4 · [[(2 · 6) - (3 · 7)] / (3 · 6)]² Subtraction of fractions with different denominators
9 / 6 - 4 · [(12 - 21) / 18]² Definition of multiplication
9 / 6 - 4 · (- 9 / 18)² Definition of subtraction
3 / 2 - 4 · (1 / 2)² Definition of simplification
3 / 2 - 4 · (1 / 4) Power properties
3 / 2 - 1 Definition of division / Existence of multiplicative inverse
3 / 2 - 2 / 2 Definition of division / Existence of multiplicative inverse
1 / 2 Subtraction of fractions with same denominator / Result
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A population of rare birds in town is currently listed at 2,000. It is declining at a rate of 2% per year. How many birds will be left after 20 years? Round your answer to the nearest whole number.
A. 1,335 birds
B. 1,980 birds
C. 2,972 birds
D. 23 birds
Option(A) is the correct answer is A. 1,335 birds.
To calculate the number of birds that will be left after 20 years, we need to consider the annual decline rate of 2%.
We can use the formula for exponential decay:
N = N₀ * (1 - r/100)^t
Where:
N is the final number of birds after t years
N₀ is the initial number of birds (2,000 in this case)
r is the annual decline rate (2% or 0.02)
t is the number of years (20 in this case)
Plugging in the values, we get:
N = 2,000 * (1 - 0.02)^20
N = 2,000 * (0.98)^20
N ≈ 2,000 * 0.672749
N ≈ 1,345.498
Rounded to the nearest whole number, the number of birds that will be left after 20 years is 1,345.
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Condense each Logarithm
The equation of logarithm are solved and
a) A = 2 + 3 log x + 4 log b
b) B = ( 36 + x + y ) ( log 6 )
c) C = ( 1/2 )x log 5
d) D = ln ( x⁴ / y² )
Given data ,
Let the logarithmic equation be represented as A
Now , the value of A is
a)
A = 2 log 10 + 3 log x + 4 log b
The base of the logarithm is 10 , so
A = 2 + 3 log x + 4 log b
b)
B = log 6³⁶ + log 6ˣ - log 6^ ( y )
From the properties of logarithm , we get
log A + log B = log AB
log A − log B = log A/B
log Aⁿ = n log A
B = 36 log 6 + x log 6 + y log 6
On taking the common term , we get
B = ( 36 + x + y ) ( log 6 )
c)
C = ( 1/2 )log 5ˣ
From the properties of logarithm , we get
C = ( 1/2 )x log 5
d)
D = 4 ln x - 2 ln y
From the properties of logarithm , we get
D = ln x⁴ - ln y²
On further simplification , we get
D = ln ( x⁴ / y² )
Hence , the logarithmic equations are solved
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Suppose you go to work for a company that pays one penny on the first day, 2 cents on the second day, 4 cents on the third day and so on.
Hint: use an= a1 (r)^n-1 and Sn= a1 (1-r^n) / 1 - r
A. If the daily wage keeps doubling, what would your income be on day 31? Give your answer in dollars NOT pennies.
Income on day 31 = $ __________
B. If the daily wage keeps doubling, what will your total income be for working 31 days? Give your answer in dollars NOT pennies.
Total Income for working 31 days = $ _________
The amount earned, calculated using the formula for geometric progressions are as follows;
(A) The income on day 31 =$1,073,741,824
(B) Total income for 31 working days = $2,147,483,647
What is a geometric progression?A geometric progression is one in which each subsequent term is a constant multiple of the previous term
(A) The function that indicates the amount earned on the nth day is the formula for a geometric progression , which can be presented as follows;
\(a_n = a_1\cdot r^{n-1}\)
The sum is presented as follows;
\(S_n =a_1\cdot \dfrac{1 - r^n}{1 - r}\)
Therefore;
The common ratio, r = 2
The first term, a₁ = 1
The amount received on day 31 is therefore;
\(a_{31} = 1\times 2^{31-1} = 1,073,741,824\)
Income on day 31 = $1,073,741,824
(B) The total income in 31 days is therefore;
\(S_{31} =a_1\cdot \dfrac{2^{31} - 1}{2- 1}== 2,147,483,647\)
The total income in 31 working days = $2,147,183,647
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weight of mr.x is 85kg in what ratio he reduce his weight if his perent weight is 65kg ?
Mr. X reduces his weight in a ratio of 4:17. This means that for every 4 units of weight he loses, his initial weight was divided into 17 equal parts.
To determine the ratio by which Mr. X reduces his weight, we need to compare his initial weight of 85 kg with his target weight of 65 kg.
The reduction in weight is calculated as the difference between the initial weight and the target weight, which in this case is 85 kg - 65 kg = 20 kg.
The ratio can be expressed as a fraction, where the numerator represents the reduction in weight and the denominator represents the initial weight:
Reduction in weight / Initial weight
Substituting the values, we have:
20 kg / 85 kg
Simplifying the fraction, we can divide both the numerator and denominator by their greatest common divisor, which is 5 in this case:
(20 kg / 5) / (85 kg / 5) = 4/17
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calcula el área de cada figura y con el resultado colorea el dibujo .Recuerda para obtener el área de un trapecio es (B+b)×a\2 para el romboide = b×a
necesito una respuesta por fa
Given the two functions, which statement is true? f(x) = 3x, g(x) = 3x + 5 Question 12 options: g(x) is translated up 5 units compared to f(x) g(x) is translated left 5 units compared to f(x) g(x) is translated down 5 units compared to f(x) g(x) is translated right 5 units compared to f(x)
The correct statement is: g(x) is translated up 5 units compared to f(x).
The correct answer is A.
To determine the translation between the two functions, we can observe that the only difference between them is the constant term.In f(x) = 3x, there is no constant term, so the graph of f(x) passes through the origin (0, 0).In g(x) = 3x + 5, there is a constant term of 5 added to the function. This means that the graph of g(x) is shifted vertically upward by 5 units compared to the graph of f(x).Therefore, g(x) is translated up 5 units compared to f(x).The correct answer is A.
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evaluate 3 square root 125/1000
Answer: it the first one
Step-by-step explanation:
Hi question is in photo please help! I’ll give brainly :)
Answer:
44 in^2
Step-by-step explanation:
Area of rectangle = 5 x 10 = 50 in^2
High of trapezoid = 10 - 6 = 4 in
Area of trapezoid = (7+15) x 4 / 2 = 22 x 4 / 2 = 22 x 2 = 44 in^2
consists of three rectangular sections that each have a different color.
In the diagram, a represents the width of the green section in inches.
Write an expression to represent the
area of the flag as the sum of the areas
of each section.
+2 (1²) + 3 (2+1²/7)
2x+2
Write an expression to represent the area
of the flag as the product of the flag's
length and width.
2+
3 )(²+
?
8
2
Green
11/12/2 Orange
3
Purple
The expression that gives the area of the rectangular flag is presented as follows:
5x + 7.5.
How to obtain the area of a rectangle?
The area of a rectangle of length l and width w is obtained by the multiplication of these dimensions, as follows:
A = l x w.
The flag in this problem is composed by three rectangles, as follows:
Green: Dimensions 2 and x.Orange: Dimensions 2 and 1 1/2 = 1 + 1/2 = 1.5.Purple: Dimensions 3 and x + 1.5.The total area is obtained by the sum of the areas of each part of the flag, hence:
Area = 2x + 2 x 1.5 + 3(x + 1.5)
Area = 2x + 3 + 3x + 4.5
Area = 5x + 7.5.
The area of each part was obtained by the multiplication of the dimensions, which is the standard procedure to obtain the area of a rectangle.
Missing InformationThe flag is given by the image at the end of the answer.
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6. If Jeremy has a batting average
of 0.5014
and Alex has a batting average of 0.50098
who has the better average?
1.3 X 2.1 = Explain your answer.
2.73
1.3x2.1=2.73
1.3
x2.1
13
+26
2.73
Answer:
To multiply 1.3 by 2.1, we need to use the distributive property of multiplication, which states that:
a × (b + c) = a × b + a × c
Using this property, we can break down 2.1 as the sum of 2 and 0.1:
1.3 × 2.1 = 1.3 × (2 + 0.1)
= 1.3 × 2 + 1.3 × 0.1
= 2.6 + 0.13
= 2.73
Therefore, 1.3 multiplied by 2.1 equals 2.73.
The ratio of black marbles to red marbles is 3:2. If there are a total of 25 marbles in a bag,
how
many
black marbles are in the bag?
Answer:
15 black marbles
Step-by-step explanation:
So its. A ratio (basically a fraction)
3/2
we add them up so we know how much marbles but not which kind
so we get 5
now we know for every 5 batches there is 3 black and 2 red
so we divide 25/5 to get 5
now we know there are 5, 5 batches of black ad red marbles.
now black is 3 of them so we multiply 5(3) which is 15
Now red is 2 of them so we multiply 5(2). Which is 10
now to check, if we add them up, they equal to 25 which is correct.
basically add the fraction, divide that by the original number, time the quotient by each number in the fraction.
Answer:
There are a total of 15 black marbles in the bag.
Step-by-step explanation:
Well, we know that for every 3 black marbles, there are 2 red marbles. In order to solve this problem, we just need to keep adding equivalent ratios with a proportional relationship until the sum of both numbers is 25.
3:2, 6:4, 9:6, 12:8, 15:10
Since 15 + 10 = 25, we can stop here.
Since the number in front of the colon is the amount of black marbles, then there are a total of 15 black marbles in the bag.
Hope this helps! :D
Sawyer got a gift card for his birthday and wants to use it for a new video game. The game costs $60, but his gift card only covers 50% of that. If his mom covers the rest and says that he can pay her 20% of that amount each week, how many weeks will it take him to pay her back?
Answer:
5 Weeks
Step-by-step explanation:
50% of $60. Sawyers gift card covers $30.
.5 x $60 = $30
That means Sawyer's mom needs to cover the remaining cost:
$60 - $30 = $30
Sawyer will pay his mom back 20% of that amount each week. To find out how much that is, we can multiply:
0.2 x $30 = $6
So Sawyer will pay his mom back $6 each week. To figure out how many weeks it will take to pay her back, we can divide the toatal amount he owes her (/30) by the amount he pays her each week (/6):
$30 ÷ $6 = 5
The dot plot shows the time trials of an experiment. Each number on the dot plot represents the amount of time, in seconds, it took to complete a trial. How many time trials were recorded during the experiment? Enter the answer in the box. time trials A number line ranging from 15 to 25 with two dots over 15, three dots over 17, two dots over 19, two dots over 20, one dot over 21, four dots over 23, one dot over 24, and three dots over 25.
There were 18 time trials recorded during the experiment.
To determine the number of time trials recorded during the experiment, we count the total number of dots on the dot plot.
According to the given information, we have:
- Two dots over 15
- Three dots over 17
- Two dots over 19
- Two dots over 20
- One dot over 21
- Four dots over 23
- One dot over 24
- Three dots over 25
By adding up these counts, we get:
2 + 3 + 2 + 2 + 1 + 4 + 1 + 3 = 18
Therefore, there were 18 time trials recorded during the experiment.
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what is 10.2719 rounded to the nearest hundredth?
Answer:
10.27
Step-by-step explanation:
10.2719 rounded to the nearest hundredth is 10.27, because to round up, the thousandths place has to be 5 or greater, but since the thousandths place is 1, you need to change the number to 10.27
Hope this helps!
The number 10.2719 rounded to the nearest hundredth is; 10.27
While considering place values of numbers,
What is the number?Numbers on the left side of the decimal are ordered from right to left as unit, tens, hundreds, thousands and so on respectively.
While Numbers on the right side of the decimal are ordered from left to right as tenth, hundredth, thousandth and so on respectively.
Therefore, according to the question, the digit with occupies the hundredth position is 7.
As such, to round off the number 10.2719, the digit which is after the digit 7 is considered.
If the digit is less than 5, it is rounded to 0, and if greater or equal to 5, it is rounded to 1 and ultimately added to the preceding number.
In this case, the number is 1 and since 1 is less than 5, it is rounded to 0 and added to 7.
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Select the interval(s) where the function is increasing:
f(x) = x ^ 4 - 5x ^ 2 - 3
(- 9.3, - 3)
(- ∞,- 1.5)
(0, 1.5)
(-1.5, 0)
(1.5, ∞)
(-∞, ∞)
(-9.3, ∞)
Last year, Philip Rivers' passing percentage was 66%, which means he completed 66% of his
passes. Using that percentage, if he throws the ball 550 times, how many times should we expect
him to complete the pass?
Answer:
363
Step-by-step explanation:
0.66*550=363
Which of the folloiwng expressions is equivalent to the radical expression?V60Х
Option B
sqrt(60) = sqrt(4 x 15) = sqrt(4) x sqrt(15)
\(\sqrt[]{60}\text{ = }\sqrt[]{4\text{ x 15}}\text{ = }\sqrt[]{4}\text{ x }\sqrt[]{15}\)What is the distance between the points (4.10) and (-3,-14) on the coordinates plane?
Answer:
25 units
Step-by-step explanation:
use the distance formula to get the square root of 24² + 7²
this will give you the square root of 625, which is 25
What is the slope of the line through the points (-8, 4) and (4, 4)?
Answer:
slope=0
hope this helps
have a good day :)
Step-by-step explanation: