Answer:
By 2020, there will be 1,147 species of birds left
Step-by-step explanation:
The general model for an exponential decrease is;
y = I(1 - r)^t
where in this case;
y is the number of bird species at a particular decade from the initial
I is the number of birds initially at 1990
r is the decrease percentage which is 1.5% per decade ; 1.5% = 1.5/100 = 0.015
t in this case will be the number of decades after the initial
Mathematically, a decade is 10 years
The difference between 2020 and 1990 is 30
The number of decades in 30 years is 30/10 = 3
so t will be 3 here
Substituting these values into the equation, we have
y = 1200(1-0.015)^3
y = 1200(0.985)^3 = 1,146.8
To the nearest whole number, this is 1,147
Is the sum of 3 consecutive numbers a multiple of 3?
The sum of 3 consecutive numbers is always of the form 3(x+1) which is always a multiple of 3.
What are consecutive numbers ?
Numbers that follow each other continuously in the order from smallest to largest are called consecutive numbers. For example: 1, 2, 3, 4, 5, 6, and so on are consecutive numbers.
Let us assume: 3 consecutive integers are x, x+1 , x+2.
on adding these three numbers we get,
x + x+1 + x+2 = 3x + 3
which can be further reduced to the form 3(x+1).
If you add any 3 consecutive numbers together it will always equal a multiple of 3, e.g.
1+2+3=6
2+3+4=9
3+4+5=12
4+5+6=15
5+6+7=18
Thus , the sum of 3 consecutive numbers is always of the form 3(x+1) which is always a multiple of 3.
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Amelia has a summer job mowing the lawn and trimming hedges for a neighbor. The number of minutes that amelia spends mowing the lawn is 10 minutes longer than three times the number of minutes it takes to trim the hedges. It takes Amelia a total of 120 minutes to complete both tasks
Using system of linear equations, Amelia spent 92.5 minutes mowing the lawn and 27.5 minutes trimming the hedges
System of Linear EquationSystem of linear equations is the set of two or more linear equations involving the same variables. A linear equation can be defined as the equations of the first order, whereby the highest power of the variable in the equation is one.
To solve this problem, we have to write a system of linear equation;
Let;
x = number of minute spent mowing lawny = number of minute trimming the hedgesWe can represent the problem with two set of equations as;
x + y = 120 ...eq(i)
x = 3y + 10 ...eq(ii)
From equation 1
x + y = 120
x = 120 - y ..eq(iii)
Put eq(iii) into eq(ii)
120 - y = 3y + 10
collect like terms
120 - 10 = 3y + y
110 = 4y
y = 110 / 4
y = 27.5 minutes
Put y = 27.5 in equ(i)
x + 27.5 = 120
x = 120 - 27.5
x = 92.5 minutes
She spent 92.5 minutes mowing the lawn and 27.5 minutes trimming the hedges.
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What's the numerator for the following rational
expression? 2/f+4/f=?/f
The numerator for the rational expression is 6
How to find the numerator for the rational expression?Let us assume the value of numerator to be x
[tex]\frac{2}{f} +\frac{4}{f} = \frac{x}{f}[/tex]
Since these are fractions with same denominators (like fractions),
[tex]= > \frac{2}{f} +\frac{4}{f} \\\\ = \frac{2 +4}{f}\\\\= \frac{6}{f}[/tex]
x = 6
The numerator for the rational expression is 6
What are fractions?Fractions are used to depict the components of a whole or group of items. Two components make up a fraction. The numerator is the number that appears at the top of the line.It indicates how many equally sized pieces of the entire thing or collection were removed. The denominator is the quantity listed below the line. The total number of identical objects in a collection or the total number of equal sections that the whole is divided into are both displayed.The number of parts we take makes up a fraction when the whole is divided into equal parts.Fractions with same denominators are called like fractions.To learn more about fractions, refer:
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What are the 7 whole numbers?
Answer:
There are an infinte amount of whole numbers
Step-by-step explanation:
7 examples are, 0, 3, 7 , 8 ,9 14, 39
I’LL MARK BRAINLIEST IF CORRECT!!
The display shows how much water is used in a household in a given day.
Which of the following describes this data set?
A) Categorical and bivariate
B) Categorical and univariate
C) Numerical and bivariate
D) Numerical and univariate
Can the sides of a triangle have lengths 2, 18, and 20?
Answer: No triangle lengths have to add all three length together to equal 180 like 60 60 60 or 90 80 10
Step-by-step explanation:
An equation for the line is
The linear equation of the given line on the graph is y = -1/2 + 5
What is a linear equation?A linear equation is an algebraic equation of the form y=mx+b.
where m is the slope and b is the y-intercept.
We have a graph.
We can see that the graph has two points:
(0, 5) = (a, b) and (4, 3) = (c, d)
The slope m is given by:
m = (d - b) / (c - a)
m = -2 / 4
m = -1/2 ,b = y-intercept
The y-intercept is at y = 5
b = 5
The linear equation is: y = mx + b
y = (-1/2) + 5
y = -1.2 + 5
Thus the linear equation of the given line on the graph is
y = -1/2 + 5
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Problem Solving in Santa's Workshop
Clifford works in the gift-wrapping department of Santa's
workshop. His job is to finish all the packages with a bow.
He is running low on bows and only has 100 bows left. He
begins working at 5:00 a.m. During the first half-hour, he
uses 12 bows. In the second half-hour, he uses 9 bows.
During the third half-hour, he uses 14 bows and in the
fourth half-hour, he uses 11 bows. Clifford uses 16 bows
during the fifth half-hour. If the pattern continues, during
which half-hour will Clifford run out of bows?
Answer:
Eighth half-hour
Step-by-step explanation:
Given pattern:
1st half hour = 12 bows used2nd half hour = 9 bows used3rd half hour = 14 bows used4th half hour = 11 bows used5th half hour = 16 bows usedCalculate the differences between the number of bows used:
[tex]12\underbrace{}_{-3}9\underbrace{}_{+5}14\underbrace{}_{-3}11\underbrace{}_{+5}16[/tex]
Therefore, the pattern for the bows used is:
-3, +5, -3, +5, etc...If the pattern continues:
[tex]12\underbrace{}_{-3}9\underbrace{}_{+5}14\underbrace{}_{-3}11\underbrace{}_{+5}16\underbrace{}_{-3}13\underbrace{}_{+5}18\underbrace{}_{-3}15\underbrace{}_{+5}20[/tex]
6th half hour = 16 - 3 = 13 bows used7th half hour = 13 + 5 = 18 bows used8th half hour = 18 - 3 = 15 bows used9th half hour = 15 + 5 = 20 bows usedCreate a table with the given and found data, and add a cumulative total column:
[tex]\begin{array}{c|c|c}\vphantom{\dfrac12} \textsf{Half Hour} & \textsf{Bows used per half hour} & \sf Cumulative\; total\\\cline{1-3} \vphantom{\dfrac12} \sf 1st & 12 & 12\\\vphantom{\dfrac12} \sf 2nd &9 &21 \\\vphantom{\dfrac12} \sf 3rd & 14&35 \\\vphantom{\dfrac12} \sf 4th & 11& 46\\\vphantom{\dfrac12} \sf 5th & 16& 62\\\vphantom{\dfrac12} \sf 6th & 13& 75\\\vphantom{\dfrac12} \sf 7th &18 & 93\\\vphantom{\dfrac12} \sf 8th & 15& 108\\\vphantom{\dfrac12} \sf 9th & 20& 128\\\end{array}[/tex]
If Clifford has a total of 100 bows, he will run out of bows during the eighth half-hour.
How do you solve an inequality with 2 answers?
Answer:
Step-by-step explanation:
Example:
If you have the inequality 3<(x/9)+7
Begin with subtraction by subtracting 7 from both sides, rather than beginning with the parentheses x/9.
Do all processes to both sides of the inequality until you have solved for x.
Example: As mentioned in the previous step, you would begin by subtracting 7 from both sides.
So 3<(x/9)+7 becomes, -4<x/9
Now you would multiply both sides by 9 because the fraction x/9 is the same as x divided by 9, and the opposite of division is of course multiplication.
This process leaves you with the solution, -36<x, so x is greater than -36.
Remember that if your problem requires you to multiply or divide by a negative number, then you need to flip the inequality sign when you do so.
For example: If instead of multiplying by 9 in the previous problem you had to multiply by -9, you would get 36>x rather than 36<x.
What is the median of first 5 numbers?
The median of 1,2,3,4,5 is 3.
The median is the middle point in a dataset—half of the data points are smaller than the median and half of the data points are larger.
Here we have to find the median of 1,2,3,4,5.
Here we can see that there are 5 numbers given
so, n= 5 which is an odd number so we will use the formula for finding the median in the case of the odd number of data.
So, M = 5+1/2 = 3
Thus the median is the 3rd term which is 3.
Therefore, the median of 1,2,3,4,5 is 3.
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Which is a quadratic equation in FACTORED FORM?
A
f(x)=2x2+5x−12f(x)=2x^2+5x-12f(x)=2x
2
+5x−12
B
f(x)=2x+5f(x)=2x+5f(x)=2x+5
C
f(x)=2(x+5)2−12f(x)=2(x+5)^2-12f(x)=2(x+5)
2
−12
D
f(x)=2(x+5)(x−12)f(x)=2(x+5)(x-12)f(x)=2(x+5)(x−12)
Answer:
Step-by-step explanation: it is b
The calls of Hazar was 2370 the last month. He received 1645 calls. The calls of Huzan was less than those of Hazar, but Huzan received more calls than Hazar. Write a system of linear inequalities to represent the situation, then solve it to determine the possible number of calls received by Huzan and the number of calls dialled by him.
The possible values of calls recieved by Huzan is more than 1645 and calls made is less than 2370.
What is Inequalities of equations ?
Mathematical expressions with inequalities are those in which the two sides are not equal. Contrary to equations, we compare two values in inequality. Less than (or less than or equal to), larger than (or greater than or equal to), or not equal to signs are used in place of the equal sign.Inequality simply means that two things aren't equal. One of the items could be inferior to, superior to, greater than, or equivalent to the other things.
p ≠ q means that p is not equal to qp < q means that p is less than qp > q means that p is greater than qp ≤ q means that p is less than or equal to qp ≥ q means that p is greater than or equal to q
Different kinds of inequality exist. Important inequities include the following: the inequalities of polynomials
Inequalities in absolute values
Logic-based disparities
Calls made by Hazar = 2370
Calls recieved by Hazar = 1645Let the number of Calls by Huzan be x.
And the number of calls recieved by Huzan be y.
Then the inequalities arex< 2370 and y> 1645
The possible values of calls recieved by Huzan is more than 1645 and calls made is less than 2370.
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What is the mean and standard deviation in which 7% of items are under 35 and 89% are under 63?
The mean and standard deviation are 50.292 and 10.362 respectively.
What is mean and standard deviation?The mean is the average of all available data value. And standard deviation is the measure of how far each data value apart from the mean value.
How to calculate mean and standard deviation of the given data value?We are given, 7% of item are under 35 and 89% of item are under 63.
Let, M refers to mean, and SD refers to standard deviation.
As per given data, P(x<35) = 35%
P(z<Z1) = 0.07
hence, Z-score= Z1 = -1.4758 [obtained from Z table]
we know that the z-score = (observed value - mean)/ standard deviation
Z1 = (x - M)/ SD
- 1.4758 = (35 - M)/ SD
-1.4758SD = 35 -M ......... equation 1
as per the 2nd condition in the given data
89% of items are under 63
so, X= 63, P(X<63)
hence, the z-score = 1.2265 [ obtained from Z table]
Z2= 1.2265= (X- mean)/ SD
1.2265SD = 63 - M.......equation 2
Solving equation 1 and 2, we get standard deviation = 10.362
Mean value = 50.292
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Which of thee i equal to co 47°?
Repone
A in 43°in 43°
B co 133°co 133°
C tan 43°tan 43°
D co 43°
Option (A) cos 47° is equal to sin 43°.
What is cos in trigonometry ?
The cos meaning in trigonometry defines the cosine of an angle. This angle is an acute angle in a right angled triangle, which is considered to find the ratios. Thus, cosine of an angle, in a right-triangle, is equal to the ratio of adjacent side of that angle and hypotenuse of the triangle.
What is sin in trigonometry ?
In trigonometry, the sine function can be defined as the ratio of the length of the opposite side to that of the hypotenuse in a right-angled triangle. The sine function is used to find the unknown angle or sides of a right triangle.
Have given,
cos 47°,
We know that cos x = sin (90 - x),
Thus cos 47° = sin (90 - 47)
cos 47° = sin 43°
Therefore, cos 47° is equal to sin 43°.
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cos 47°,
We know that cos x = sin (90 - x),
Thus cos 47° = sin (90 - 47)
cos 47° = sin 43°
Therefore, cos 47° is equal to sin 43°.
What is the median of the following set of scores 19 5/12 10 and 14?
The median of this set of scores 19,5/12,10 and 14 is 12.
To find the median of a set of scores, you first need to arrange the scores in numerical order. The median is the middle score in the set. If there is an odd number of scores, then the median is the middle score. If there is an even number of scores, then the median is the average of the two middle scores.
In this case, the scores are 5/12, 10, 14, and 19.
After arranging the scores in numerical order, we have 5/12, 10, 14, and 19.
There are four scores in this set, so the median is the average of the two middle scores, which are 10 and 14.
The median of the set is: (10 + 14) / 2 = 12.
The median of this set of scores is 12.
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Are all equilateral triangles congruent Why?
For a triangle to be equilateral all its angle should be same which is 60° but for them to be congruent their sides should also be same in measure.
Therefore two equilateral triangles are not always congruent with one another as because there can be difference in the measure of their sides.
The sum of angles of a triangle is 180 degree which is the sum of angles of the triangle's three angles.
There are three types of triangles based on different aspects .
Based on the lengths of their sides, triangles can be classified as
ScaleneIsoscelesEquilateralAs in an equilateral triangle all of the sides are of the same length. and all the angle measure will be 60 degrees. An equilateral triangle is also known as an equiangular triangle since its angles are all the same.
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The coordinate 3 has a weight of 2,
and the coordinate 9 has a weight of 1.
Find the weighted average.
PLEASEEE HELPPP
Answer:
1.5
Step-by-step explanation:
avj=total/n n=no of thingsavj=1+2/2avj=3/2 or 1.5Answer: Answer is
Step-by-step explanation:
I don't know how to explain it but I went over it with my teacher and it is
a normal distribution of scores has a standard deviation of 10. find the z-score corresponding to a score that is 30 points below the mean.
The z-score 30 points below the mean is -3
The normal distribution of scores has a standard deviation(σ) of 10
Below the mean is (X-μ)=-30
The mean (average) of a data set is found by adding all numbers in the data set and then dividing by the number of values in the set.
Z=(X-μ)/σ
Z=-30/10
Z=-3
Therefore, the z-score is -3.
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You plan projects revenue of $5,000, $8,000, and $10,000, in years 1 through 3. Expenses are projected to be $9,000 for each of years 1 through 3. If your only funding need is the gap between revenue and expenses, which is the best estimate of your maximum cumulative funding need?
The best estimate of your maximum cumulative funding needed, based on the projected revenue and the expenses is $ 4, 000.
How to find the maximum cumulative funding needed ?The maximum cumulative funding needed would be the amount that would be total gap between revenue and expenses in the three years that the plan will be in effect.
In year 1, the gap is :
= 5, 000 - 9, 000
= $ - 4, 000
In year 2, the gap is:
= 8, 000 - 9, 000
= $ - 1, 000
In year 3, the gap is:
= 10,000 - 9, 000
= $ 1, 000
The cumulative funding needed is :
= ( -4,000 + - 1, 000 ) + 1, 000
= - $4, 000
You have a maximum cumulative funding needed of $ 4, 000.
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Do you think it is necessary to learn the concepts of measurement?
It offers a rich and meaningful environment for the application of spatial and mathematical concepts due to this it is necessary to learn the concepts of measurement.
what are concepts of measurement?Linking the various branches of mathematics together requires measurement. For instance, it offers a rich and meaningful framework for the application of math abilities and spatial concepts. Links between mathematics and other academic areas are also provided via measurement.
It makes comparison easier since we no longer need to locate several items to serve as the reference; instead, we may compare multiple objects by only comparing the numbers of a single established unit.
It offers a rich and meaningful environment for the application of spatial and mathematical concepts due to this it is necessary to learn the concepts of measurement.
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Can a 5 year old count to 100?
Yes, a 5 year old can typically count to 100.
What is counting?Counting is the process of determining the number of elements in a given set or group of objects. Counting is a basic numerical skill that is used in mathematics and other fields. It involves recognizing patterns and comparing numbers to identify how many items are in a given set. Counting is an important part of early childhood education, as it introduces children to the concepts of number and quantity.
Depending on the child's exposure to numbers, they may be able to count even higher. Counting to 100 is a fundamental skill that can be developed through practice and repetition. Teaching a 5 year old to count to 100 can be done through activities such as counting objects, counting steps, and playing counting games.
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In 2005, 13.1 out of every 50 employees at a company were women. If there are 46,043 total company employees, estimate the number of women.
Each interior angle of a regular polygon is 120°.
Find the value of each exterior angle of the polygon.
Answer:
exterior angle = 180° - 120°
= 60°
Answer:
60 degrees
Step-by-step explanation:
180-120=60
Find the slope from two points
Answer: 7/ -8
Step-by-step explanation:
The slope is rise/run
Our two points are (10,9) ( 2,16)
We see that y increased by 7, and the x decrease by 8
So the slope is 7/ -8
Finding an angle measure given a triangle and parallel lines
Answer:
[tex]x\textdegree = 120\textdegree[/tex]
Step-by-step explanation:
Because alternate exterior angles (of a transversal that intersects parallel lines) are congruent, the bottom left interior angle of the triangle is 55º.
Using this information, we can solve for the bottom right interior angle of the triangle (denoted θ) by setting the sum of the measures of the triangle's interior angles to 180º.
[tex]55\textdegree + 65\textdegree + \theta = 180\textdegree[/tex]
↓ subtract 55º and 65º from both sides
[tex]\theta = (180-55-65)\textdegree[/tex]
↓ simplify
[tex]\theta = 60\textdegree[/tex]
Now that we have the measure of the triangle's bottom right interior angle, we can solve for xº because an interior angle of a triangle and its corresponding exterior angle are supplementary (their angle measures add to 180º).
[tex]\theta + x\textdegree = 180\textdegree[/tex]
↓ plug in the solved value for θ
[tex]60\textdegree + x\textdegree = 180\textdegree[/tex]
↓ subtract 60º from both sides
[tex]x\textdegree = (180 - 60)\textdegree[/tex]
↓ simplify
[tex]x\textdegree = 120\textdegree[/tex]
Find an equation of variation for the given situation.
y varies directly as x, and y = 0.1 when x = 0.5.
The equation of variation for the given situation is y = 5x.
Direct ProportionIn mathematics, a direct proportion is a comparison of two integers where the ratio of the two numbers equals a constant value. According to the concept of proportion, two ratios are in proportion when they are equal.
If a varies directly to b then the relation between them can represent as
=> a ∝ b
=> a = kb [ where 'k' is proportionality constant]
Here we have
y varies directly as x, this can be shown as
=> y ∝ x
=> y = kx ---- (1) [ Where 'k' is proportionality constant ]
Given that y = 0.1 and x = 0.5
Substitute the above values in (1)
=> 0.1 = k(0.5)
=> k = 0.5/ 0.1
=> k = 5
(1) => y = 5x
Therefore,
The equation of variation for the given situation is y = 5x.
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What is a correct first step in solving the inequality 4 3 5x ≥ 6x 9 brainly?
The first step in solving the inequality is -12 + 20x ≥ -6x + 9
An inequality can be defined as a relationship that shows a non-equal comparison between two numbers or mathematical expressions.
Given the inequality
–4(3 – 5x)≥ –6x + 9
Solving the inequality
⇒-12 + 20x ≥ -6x + 9
Keeping all x on one side it can be written ,
⇒20x + 6x ≥ 12 + 9
Adding both sides,
⇒26 x ≥ 21
divide both sides by 26,
⇒x ≥ 0.80
So, the first step in solving the inequality is -12 + 20x ≥ -6x + 9
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The correct question is :
What is the correct first step in solving the inequality –4(3 – 5x)≥ –6x + 9?
Can 55 years old get SSS?
No They can not because you need to be at least 62 years old
A number, .f, rounded to 1 d.p. is 49.2
Another number, g,
rounded to 1 d.p. is 7.8
What are the lower and upper bounds of
f - g?
Answer:
3
Step-by-step explanation:
The lower bound of f-g is 41.31 .
The upper bound of f-g is 41.49 .
Given,
A number 'f' rounded to 1 decimal point is Number = 49.2
A number 'g' rounded to 1 decimal point is Number = 7.8
Now,
The range of f rounded to 1 decimal point is [49.15 , 49.24].
The range of g rounded to 1 decimal point is [7.75 , 7.84].
So,
Lower bound of f-g = 49.15 - 7.84
Lower bound of f-g = 41.31
Next,
Upper bound of f-g = 49.24 - 7.75
Upper bound of f-g = 41.49
Therefore the lower bound of f - g is 41.31 and upper bound of f - g is 41.49.
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A proportional relationship is shown here:
x = 0, 1.4, 2.8, 4.2, 5.6
y = 0, 1, 2, 3, 4
What is the slope of the line that represents this relationship?
Graph the line that represents this relationship.
Answer:
y=1.4x
Step-by-step explanation:
Find the relationship.
1.4/1=1.4
2.8/2=2.8
and so on so we know it is 1.4
so y=1.4x