1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
nexus9112 [7]
3 years ago
8

The idea of a large, stable middle class (defined as those with annual household incomes in 2010 between $42,000 and $126,000 fo

r a family of three), is central to America's sense of itself. But the U.S. middle class shrank steadily from 61% of all adults in 1971 (t = 0) to 51% in 2011 (t = 4), where t is measured in decades. Research has shown that this decline was approximately linear.† (a) Find a linear function f(t) giving the percentage of middle-income adults in decade t, where t = 0 corresponds to 1971.
Mathematics
1 answer:
ser-zykov [4K]3 years ago
7 0

Answer:

f(t) = -0.025t + 0.61

In which t is measured in decades.

Step-by-step explanation:

A linear function f(t) has the following format:

f(t) = at + b

We are given two points of the function, so we can solve a system of equations to find the values for a and b.

61% of all adults in 1971 (t = 0)

This means that f(0) = 0.61

So

f(t) = at + b

0.61 = a*(0) + b

b = 0.61

51% in 2011 (t = 4)

This means that f(4) = 0.51

So

f(t) = at + 0.61

0.51 = 4a + 0.61

4a = -0.10

a = -0.025

So the linear function is:

f(t) = -0.025t + 0.61

In which t is measured in decades.

You might be interested in
A regular hexagon is shown.
s2008m [1.1K]
Since the triangle will be a 30-60-90, because 360°/6 = 60° for each central angle, then that is bisected to find the height of each of the 6 equilateral triangles. This height is the same as the apothem.
In a 30-60-90 triangle, the sides are is the ratio of:
x \:  \\ x \sqrt{3} \\ and \: 2x
where x is opposite the 30° and 2x is opposite the 90°
Since the base is 10 and the hypotenuse is 10, 1/2 that is 5 (the x), and so:
x \sqrt{3}  = 5 \sqrt{3}  = 8.66
So rounded up, you apothem then is closest to D) 9 in.
3 0
3 years ago
Read 2 more answers
Which mathematical term can be defined precisely?
Inessa05 [86]

Answer:

I think it is option A

<em><u>point</u></em>

<em><u>hope</u></em><em><u> it</u></em><em><u> helps</u></em>

8 0
3 years ago
Read 2 more answers
Can you simplify 10/24
pentagon [3]

Answer: 5/12

Step-by-step explanation: basically divide each number (10 &24) by 2

5 0
2 years ago
A total of 1 232 students have taken a course in Spanish, 879 have taken a course in French, and 114 have taken a course in Russ
ElenaW [278]

Answer:

n(S\cap F \cap R)=7

Step-by-step explanation:

The Universal Set, n(U)=2092

n(S)=1232\\n(F)=879\\n(R)=114

n(S\cap R)=23\\n(S\cap F)=103\\n(F\cap R)=14

Let the number who take all three subjects, n(S\cap F \cap R)=x

Note that in the Venn Diagram, we have subtracted n(S\cap F \cap R)=x from each of the intersection of two sets.

The next step is to determine the number of students who study only each of the courses.

n(S\:only)=1232-[103-x+x+23-x]=1106+x\\n(F\: only)=879-[103-x+x+14-x]=762+x\\n(R\:only)=114-[23-x+x+14-x]=77+x

These values are substituted in the second Venn diagram

Adding up all the values

2092=[1106+x]+[103-x]+x+[23-x]+[762+x]+[14-x]+[77+x]

2092=2085+x

x=2092-2085

x=7

The number of students who have taken courses in all three subjects, n(S\cap F \cap R)=7

3 0
3 years ago
Multiply Conjugates Using the Product of Conjugates Pattern
Aleksandr [31]

Answer:

The product is the difference of squares is $$\left(5k+6\right)\left(5k-6\right)=25{{k}^2}-36$$

Step-by-step explanation:

Explanation

  • The given expression is (5 k+6)(5 k-6).
  • We have to multiply the given expression.
  • Square the first term 5k. Square the last term 6 .

$$\begin{aligned}&(5 k+6)(5 k-6)=(5 k)^{2}-(6)^{2} \\&(5 k+6)(5 k-6)=25 k^{2}-36\end{aligned}$$

8 0
2 years ago
Other questions:
  • What is the arc length of a circle (in meters) with a radius of 2 meters that has an arc angle of 90°?
    10·1 answer
  • Two angles are complementary. One angle is ten less than four times the other angle. Find the measure of the larger angle
    12·1 answer
  • Add [-6 -2 2] + [ -3 2 1]
    14·1 answer
  • How to find the percentage of a number​
    15·1 answer
  • Question 3 of 10 Which of the following best describes the graph below? +2 54 -3 -2 -1 1 O A. It is a one-to-one function. O B.
    12·2 answers
  • What is the ratio of 50 cents to $1.20 (in simplest form)?
    11·1 answer
  • Epic math question that i cant solve
    8·1 answer
  • Rewrite the equation below so that it does not have fractions. 2/3x-4=5/6 Do not use decimals in your answer.
    9·1 answer
  • "FREE 100 POINTS" if you help me
    9·2 answers
  • An x-method chart shows the product a c at the top of x and b at the bottom of x. Above the chart is the expression a x squared
    8·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!