Mark each! Of the following equations as true or false. Explain or showing your reasoning!

Answer:

(a) 100

(b) 10.27

Step-by-step explanation:

We are given  

No of elements = 15  

Σ(x-c) = 72,Σ(x-c)^2 = 499.6

,where c is a constant

and the sample mean is 104.8.

(a)  lets take into account Σ(x-c) = 72

this means that we have the sum of the 15 elements of x and each element of x is subtracted by the constant c

so the equation becomes Σxi -15c = 72, ............(1)

where xi means the sum of the elements of x from 1 to 15.

we are given the mean as 104.8

this means that Σxi/15 = 104.8

Σxi = 15*104.8 = 1572 .............(2)

substituting (2) in (1)

we get  

1572 - 15c = 72  

15c = 1500  

c = 100

(b) We will use the property that variance does not change when a constant value is added or subtracted to the elements. This we can observe in the given equation that c is a constant that has the value of 100.

so the variance is  

σ^2 = Σ(x-c)^2/15  - (Σ(x-c)/15 )^2

      = 499.6/15  - (72/15)^2

      = 33.31 - 23.04

   σ^2   = 10.27

Therefore the variance of the given problem is 10.27.

Answer:

320 odd three.

Step-by-step explanation:

9 but we cannot place the digits that are used in the two other digits and we can place only 7 digits. However, the result is not correct, because there are 320 odd three-digits numbers with different digits.

Answer: 390625

The quiz has 5 choices for each question, so there are 5 ^ 8   ways to answer the quiz questions.

In other words, you can calculate the possible numbers of answers = 5x5x5x5x5x5x5x5 = 390625

Step-by-step explanation:

mmmmmmmmmmmmmmmmmmmmmmmmmmm

Answer:

Sum = 4 + 5 = 9

Step-by-step explanation:

Equation

2*(x - 2)(x-2) = (x - 3)(x + 4)

Solution

2*(x^2 - 4x + 4) = x^2 + 4x - 3x - 12

2x^2 - 8x + 8  = x^2 +x - 12                     Subtract the right side from the left

x^2 - 9x + 20 = 0

(x - 4)(x - 5) = 0

The possible values for x are

x - 4 = 0

x = 4

x - 5 = 0

x = 5

Check

(4 - 2)^2 = (4) = 4

(x - 3)(x + 4) = (4 - 3)(8) = 8

This checks

(5 - 2)^2 = 3^2 = 9

(5 - 3)(5 + 4) = 2 * 9 = 18

Answer:

the answer is A:

sinA=h/c

sinC=h/a

Step-by-step explanation:

edge 2020

The pair of equations is sinA=h/a cosC=h/a

What is trigonometry?

Trigonometry is the branch of mathematics that deals with particular angles' functions and how to use those functions in calculations. There are six popular trigonometric functions for an angle. Sine (sin), cosine (cos), tangent (tan), cotangent (cot), secant (sec), and cosecant are their respective names and acronyms.

When a altitude is drawn from the base of the triangle

we can write

sinA=height/ a where a, is the side length of AB

also,cos C=height/a where a, is the side length of AB

Therefore,The pair of equations is where a, is the side length of AB

Learn more about trigonometry,

https://brainly.com/question/20519838

#SPJ2

Simple Proof:

a) In the image, we know that ABCD is a parallelogram and that means opposite angel measures should be the same. We know that angel DCB is made up by angel 1 and 2, and angel DAB and DCB are equal and angel DAB is made up by angel 1 and x. So now we can conclude that angel x is equal to angel 2.

b) According to the definitions of a parallelogram, opposite angel measures have to be the same, while AECF have angle 1 to angel 1 and angel 2 to angel 1. We can conclude that AECF is NOT a parallelogram. (Sorry, you didn't give me the full question so some information remains unclear. )

Answer:

-6=2/3*-6

Step-by-step explanation:

y=mx+b

slope = m b=y intercept

Answer:

6c for the total

Knowing the roots first write the equation in factored form:

(X - 3/4)(x +5) = 0

Now use the FOIL method ( multiply each term in one set of parentheses by each term the other set:

X•x + x•5 -3/4•x -3/4•5

Simplify:

X^2 + 5x -3/4x -3 3/4

Combine like terms:

X^2+ 4 1/4x - 3 3/4

Answer:

4

Step-by-step explanation:

12(1/3)

so it is just 12/3 which is 4

Hope that helps :)

Answer:

3 years old and 8 years old

Step-by-step explanation:

8-3=5

3x8=24

plz mark me as brainliest

Answer:

[tex]5\sqrt[3]{5}[/tex]

Step-by-step explanation:

[tex]\sqrt[3]{625}[/tex] factor [tex]625^{1/3}[/tex]=[tex]5(5^{1/3} )[/tex]=5\sqrt[3]{5}

Hope that helps :)

edg2021

Answer:

Step-by-step explanation:

Rewrite this quadratic in standard form:  3x^2 + 7x - 1.

The coefficients of x are {3, 7, -1}, and so the discriminant is b^2 - 4ac, or

7^2 - 4(3)(-1), or 49 + 12, or 61.  Because the discriminant is positive, this quadratic has two real, unequal roots

Answer:

The axis of symmetry is x=3, the vertex of the graph is (3,-2)

Step-by-step explanation:

[tex]f(x)=(x^{2} -6x+9)-9+7[/tex]

[tex]=(x-3)^{2} -2[/tex]

Answer:

45

Step-by-step explanation:

3 out of 12 is 1/4, or 0.25, so if you divide 180 by 4, then using the same logic, you can expect 45 kids to have played last year.

3 = 1/4 OR .25 of 12, 12 divided by 4 = 3

180 divided by 4 = 45

Answer:

yes its 45 i did the test and i got an 100

Step-by-step explanation:

heres proof

Answer:

Step-by-step explanation:

common difference d=3-1=2

first term a=1

an=a+(n-1)d

2n-1=1+(l-1)2

2n-1=1+2l-2

2n-1=2l-1

l=n

(i used l for number of terms)

number of terms=n

[tex]S_{n}=\frac{n}{2} (first ~term+last~term)\\=\frac{n}{2} (1+2n-1)\\=n^2[/tex]

28.571429% that is 2

hope this helped

Answer:

50% Is the answer

Step-by-step explanation:

-√81=-√(9)²=-9

A number inside a Square root cannot ne negative. So, the second one is not a real no.

Answer:

[tex] - \sqrt{81} = - 9 \\ \sqrt{ - 25 = - 5} [/tex]

Step-by-step explanation:

-81/9 9+9+9+9+9+9+9+9+9(81)

-9

-25/5 (5+5+5+5+5(25)

-5

Answer:

2a°+2a°=180°[opposite angle of cyclic quadrilateralis 180°]

4a°=180

a=180°/4

a=45°

4b+2b=180°[similarly]

6b=180°

b=180°/6

b=30

9514 1404 393

Answer:

  B  80 square inches

Step-by-step explanation:

The area of a parallelogram has the same formula as the area of a rectangle:

  A = bh . . . . . b is the base; h is the height

  A = (10 in)(8 in)

  A = 80 in²

The minimum amount of material needed is 80 square inches.

Answer:

The answer is 80

Step-by-step explanation:

Hope this helps

Answer:

The customer can conclude that the company's claim is correct

Step-by-step explanation:

The percentage of lids that has a free yogurt coupon = 20%

The number of cups a loyal customer purchases = 85 yogurt cups

The number of cups that contained a coupon = 12 (14.1%)

The confidence interval performed = 99% confidence interval for the proportion of yogurt cups containing coupon codes

The interval obtained = (0.044, 0.238)

Therefore, the range of proportion within which the true proportion exists is 0.044 < [tex]\hat p[/tex] < 0.238

The range of percentage within which the true percentage exist is therefore;

0.044 × 100 = 4.4%  < [tex]\hat p[/tex] × 100 < 0.238 × 100 = 23.8%

Given that the possible true percentage of lids that has a coupon is between 4.4% and 23.8% at 99% confidence level, the customer can conclude that only 12 of his yogurt cup contained coupon by chance and that the company's claim is correct.

Answer:

A, the company’s claim may be justified because 0.2 is in the confidence interval.

Step-by-step explanation:

Answer:

Science students

Step-by-step explanation:

Answer: n=4

Step-by-step explanation:

Given

3n-(2+n)=6

Expand Parenthesis (REMEMBER TO CHANGE SIGNS)

3n-2-n=6

Combine like terms

2n-2=6

Add 2 on both sides

2n-2+2=6+2

2n=8

Divide both sides by 2

2n/2=8/2

n=4

Hope this helps!! :)

Please let me know if you have any questions

Answer:

4

Step-by-step explanation:

4 Is the Answer because you have to multiply 4 to all the N's. Which means you have to multiply 4 by 3 which equals 12. Then 2+4=6. Then you would do 12-6=6. There's your answer. Here is the equation if it were like the problem: 12 - (2+4). I'm sure you can figure out the rest. Thanks. If you find any fault in my answer let me know! Have a good day!

=> 9x² - 24x + 16

Split the middle term(term with x) in such a manner so that the product of those parts is equal to the product of term with x² and constant. Here, those parts are 12 & 12 as 12*12 = 9*16.

=> 9x² - 24x + 16

=> 9x² - (12 + 12)x + 16

=> 9x² - 12x - 12x + 16

=> 3x(3x - 4) - 4(3x - 4)

=> (3x - 4)(3x - 4)

Method 2

=> 9x² - 24x + 16

=> (3x)² - 2(3x*4) + 4²

=> (3x - 4)²

=> (3x - 4)(3x - 4)

Method 3

In case if you can't find the factors of the middle term.

Say f(x) = 0, find the zeroes using quadratic formula. Zeroes of this eqⁿ are [-(-24) ± √24²-4(9)(16)] / 2(9) = 4/3 & 4/3

Therefore, f(x) = (x - 4/3)(x - 4/3) = (3x - 4)(3x - 4)/9

Ignore the numeric constant.

f(x) = (3x - 4)(3x - 4)