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
Yuri [45]
2 years ago
7

Please teach me on how to answer this question. (addmath question)

Mathematics
1 answer:
arsen [322]2 years ago
5 0

We know that \overline{x}=8 so:

\overline{x}=8\\\\\\\dfrac{\sum\limits_{k=1}^7\,x_k}{7}=8\qquad|\cdot7\\\\\\ \boxed{\sum\limits_{k=1}^7\,x_k=56}

We want to calculate:

\sum\limits_{k=1}^7\,\big(2x_k-3\big)^2=\sum\limits_{k=1}^7\,\big(4x_k^2-12x_k+9\big)=\\\\\\=\sum\limits_{k=1}^7\,4x_k^2-\sum\limits_{k=1}^7\,\big12x_k+\sum\limits_{k=1}^7\,9=4\sum\limits_{k=1}^7\,x_k^2-12\sum\limits_{k=1}^7\,x_k+\sum\limits_{k=1}^7\,9=\\\\\\=4\cdot672-12\cdot56+7\cdot9=2688-672+63=\boxed{2079}

You might be interested in
The side length of a square ice cube is claimed to be 1.0 inches, correct to within 0.001 inch. Use linear approximation to esti
Olenka [21]

Answer:

0.012

Step-by-step explanation:

Linear approximation says that,

f(x) \approx f(x_o)+f'(x_o)(x-x_o)

For a cube the surface area is 6x^2.

So the side is 1.0 inch in, the surface area is =6\times1^2 = 6 square inches.  

In Linear approximation means you ignore the term x_o^2 , if x_o is a small number, because then x_o^2 will be a very smalle number and that does not contribute much to the error.  

So the surface area is approximately,

6x^2=6x_o^2+12x_o(x-x_o)

So here, x=1.001, x_o=0.001

The error in the area is approximately,

12 \times 0.001=0.012

So the error is 0.012.


3 0
3 years ago
Suppose that y is inversely proportional to square root of x.
FromTheMoon [43]

Answer:

i) k = 36.8

ii)y = 36.8/square root of x

iii)y = 1.4

Step-by-step explanation:

If y is inversely proportional to square root of x;

then the two variables are related by,

y = k/ square root of x

i)Value of k when...x = 8 and y = 13,

substitute into the equation above..so as to find the value of k

13 = k/square root of 8

;k = 13 × square root of 8

;k = 36.8

ii)Then substitute the value of k with...36.8

y = 36.8/square root of x

iii)If x = 27...then y =;

y = 36.8/27

y = 1.4

7 0
3 years ago
Evaluate 2d+3 when d = 8
IgorC [24]
2d+3
2(8)+3
Multiply 2 and 8
16+3
19
So the answer is 19
5 0
3 years ago
Read 2 more answers
A club charges $40 for membership fee and $3/hour for using it. If he used the club for 60 hours what is the total cost.
Arlecino [84]
Total cost is 220 dollars. This is because 3 times 60 is 180 and plus membership fee of 40 dollars is 220 dollars.
7 0
3 years ago
Read 2 more answers
Select the correct answer.
BARSIC [14]

Answer:

D)    4x  + 2y  ≤  25   ,      x + y ≥  8     is the required system of inequalities  

        to represent the given situation.

Step-by-step explanation:

Here, let  the number of color copies =  x

Now, the time taken to print each color copy = 4 minutes

⇒Time taken to print x color copies = x times ( Time taken by each copy)

= 4 (x)   = 4x

and let  the number gray scale copies =  y

The time taken to print each gray scale copy = 2 minutes

⇒Time taken to print y gray scale copy = y times (Time taken by each copy)

= 2 (y)   = 2y

Total copies printed = x + y

Maximum time taken to print x  color copies and y grayscale copies

= 4x  + 2y

So, according to the question:

4x  + 2y  ≤  25 ( as maximum allotted time is 25 minutes)

and x + y ≥  8      (as minimum number of copies is 8)

hence, the above system is the required system of inequalities to represent the given situation.

7 0
3 years ago
Other questions:
  • 3 divided by 3/4 is what.
    11·2 answers
  • PLEASE HELP!! WILL MARK BRAINLIEST AND HELP YOU!!!
    6·1 answer
  • 7th grade math question please help me?!
    11·1 answer
  • A student got 22 out of 25 questions correctly, shade the model to help write the decimal that repersents the fraction of correc
    6·1 answer
  • In the figure, p || q.
    15·1 answer
  • I need help with this question
    5·1 answer
  • 1. Under absorption costing, how much fixed manufacturing overhead cost is included in the company's inventory at the end of las
    13·1 answer
  • Write improper fraction as a mixed number 85/40
    9·2 answers
  • {(3, 5), (3, 7), (6, 7), (4, 1), (8, 1)}
    8·1 answer
  • 2. Choose all that apply: What are the coordinate point(s) that cross the x-axis
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!