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
STALIN [3.7K]
3 years ago
13

On a 10-item test, three students in Professor Hsin's advanced chemistry seminar received scores of 2, 5, and 8, respectively. F

or this distribution of test scores, the standard deviation is equal to the square root of A) 4. B) 5. C) 6. D) 9
Mathematics
2 answers:
Inessa [10]3 years ago
4 0

Answer:

For this distribution of test scores, the standard deviation is equal to the square root of 9

D) 9

Step-by-step explanation:

We need to know the standard deviation formula:

S=\sqrt{\frac{sum(x-Am)^2}{n-1} } (1)

Where:

S: Standard deviation

sum: Summation

x: Sample values

Am: Arithmetic mean

n:   Number of terms, in this case 3

Now, we need to know the arithmetic mean of the sample values: 2, 5 and 8

Am=\frac{2+5+8}{3} = 5

To know the standard deviation we need to have the summation of each term minus the arithmetic mean squared.

(x-Am)^2 of each term:

(2-5)^2=9\\(5-5)^2=0\\(8-5)^2=9

Now, we can find the standard deviation:

S=\sqrt{\frac{9+0+9}{3-1} } \\S=\sqrt{\frac{18}{2} } \\S=\sqrt{9}

The standard deviation is equal to the square root of 9

docker41 [41]3 years ago
3 0

Answer:

D) 9

Step-by-step explanation:

Standard Deviation is Calculated by formula:  

Standard deviation(\sigma) = Standard deviation(\sigma) = \sqrt{\frac{1}{n-1}\sum_{i=1}^{n}{(x_{i}-\bar{x})^{2}} }

where, \bar{x} is mean of the distribution.

First: Calculating Mean of 2, 5 and 8:

\text{Mean}(\bar x)=\frac{2+5+8}{3} = 5

Then Standard deviation is:

Standard deviation(\sigma) = \sqrt{\frac{1}{3-1}\sum_{i=1}^{n}{(x_{i}-5)^{2}} }

⇒ \sigma = \sqrt{\frac{1}{2}[{(2-5)^{2}}+{(5-5)^{2}}+{(8-5)^{2}} } =\sqrt 9

You might be interested in
A recursive arithmetic sequence is defined ad f(1)=6, f(n+1)=f(n)+5 for n>1. The first four terms of the sequence are shown i
Dennis_Churaev [7]
Write the first few terms of the sequence.
f₁ = 6
f₂ = f₁ + 5 = 11
f₃ = f₂ + 5 = 16
f₄ = f₃ + 5 = 21
and so on

The sequence is
6, 11, 16, 21, ...,
This is an arithmetic sequence with a common difference of 5.

In function notation, the sequence is
f_{n+1} = 6 + 5n, \\ \, n=0,1,2, \, ...,

This represents the equation of a straight line with n as the independent variable and f as the dependent variable.
The slope is 5. 
A graph of the line is shown below.

Answer:
The sequence is f_{n+1} = 6 + 5n, \,\, n=0,1,2, \, ...,
The slope is 5.

7 0
3 years ago
Read 2 more answers
The area of a square is 73.96 m^2 .calculate the length of its side.​
Alexus [3.1K]

It a bc i said so hahahahaha

7 0
3 years ago
QUICK QUICK! 1 MINUTE ONLY PLEASE!
Gekata [30.6K]

2 laps per minute

2 laps------60 s

1 laps -----x s

x=(1*60)/2

x=30 s

30s=1/2 min

D.

5 0
3 years ago
Read 2 more answers
Donald sells 760 marbles everyday. He sells each marble for 1.5 dollars. For how many days does Donald need to sell marbles to e
Harman [31]

Answer:

Donald needs 3 days to earn 3420 dollars

Step-by-step explanation:

Donald sells 760 marbles everyday. He sells each marble for 1.5 dollars

amount collected in one day= 760 \cdot 1.5=1140 dollars

In one day the amount earned is 1140 dollars

we need to find the number of days needs to earn 3420 dollars

Number of days needed is \frac{3420}{1140}=2.842

So its around 3 days

Donald needs 3 days to earn 3420 dollars

8 0
3 years ago
How do I find the integral<br> ∫10(x−1)(x2+9)dxint10/((x-1)(x^2+9))dx ?
defon
\int\frac{10}{(x-1)(x^2+9)}\ dx=(*)\\\\\frac{10}{(x-1)(x^2+9)}=\frac{A}{x-1}+\frac{Bx+C}{x^2+9}=\frac{A(x^2+9)+(Bx+C)(x-1)}{(x-1)(x^2+9)}\\\\=\frac{Ax^2+9A+Bx^2-Bx+Cx-C}{(x-1)(x^2+9)}=\frac{(A+B)x^2+(-B+C)x+(9A-C)}{(x-1)(x^2+9)}\\\Updownarrow\\10=(A+B)x^2+(-B+C)x+(9A-C)\\\Updownarrow\\A+B=0\ and\ -B+C=0\ and\ 9A-C=10\\A=-B\ and\ C=B\to9(-B)-B=10\to-10B=10\to B=-1\\A=-(-1)=1\ and\ C=-1

(*)=\int\left(\frac{1}{x-1}+\frac{-x-1}{x^2+9}\right)\ dx=\int\left(\frac{1}{x-1}-\frac{x+1}{x^2+9}\right)\ dx\\\\=\int\frac{1}{x-1}\ dx-\int\frac{x+1}{x^2+9}\ dx=\int\frac{1}{x-1}-\int\frac{x}{x^2+9}\ dx-\int\frac{1}{x^2+9}\ dx=(**)\\\\\#1\ \int\frac{1}{x-1}\ dx\Rightarrow\left|\begin{array}{ccc}x-1=t\\dx=dt\end{array}\right|\Rightarrow\int\frac{1}{t}\ dt=lnt+C_1=ln(x-1)+C_1

\#2\ \int\frac{x}{x^2+9}\ dx\Rightarrow  \left|\begin{array}{ccc}x^2+9=u\\2x\ dx=du\\x\ dx=\frac{1}{2}\ du\end{array}\right|\Rightarrow\int\left(\frac{1}{2}\cdot\frac{1}{u}\right)\ du=\frac{1}{2}\int\frac{1}{u}\ du\\\\\\=\frac{1}{2}ln(u)+C_2=\frac{1}{2}ln(x^2+9)+C_2

\#3\ \int\frac{1}{x^2+9}\ dx=\int\frac{1}{x^2+3^2}\ dx=\frac{1}{3}tan^{-1}\left(\frac{x}{3}\right)+C_3\\\\therefore:\\\\\#1;\ \#2;\ \#3\Rightarrow(**)=ln(x-1)+C_1-\frac{1}{2}ln(x^2+9)+C_2-\frac{1}{3}tan^{-1}\left(\frac{x}{3}\right)+C_3

\boxed{=ln(x-1)-\frac{1}{2}ln(x^2+9)-\frac{1}{3}tan^{-1}\left(\frac{x}{3}\right)+C}



4 0
3 years ago
Other questions:
  • HELP PLEASE
    8·1 answer
  • How do I factor out the coefficient of the variable -5p+20
    9·1 answer
  • Josie is 11 years older than macy
    7·1 answer
  • How do I find the radius of a circle
    14·2 answers
  • Number the following expressions (1,2,3) in the order that they should be
    11·1 answer
  • I need help finding the per hour
    6·1 answer
  • Plz help..............
    12·2 answers
  • Can anyone help. me pass
    9·1 answer
  • "A cylindrical container has a radius of 25 inches and a height of 31 inches. What is the volume of
    14·1 answer
  • (4x + 3y)^2 please tell me the wander ✌️​
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!