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
Arisa [49]
2 years ago
12

Yuri computes the mean and standard deviation for the sample data set 12, 14, 9, and 21. He finds the mean is 14. His steps for

finding the standard deviation are below. What is the first error he made in computing the standard deviation?
A. Yuri failed to find the difference between each data point and the mean.
B. Yuri divided by n instead of n -1.
C. Yuri did not subtract 9 - 14 correctly.
D. Yuri failed to square -2 correctly.

Mathematics
2 answers:
Amiraneli [1.4K]2 years ago
7 0

Answer:

C

Step-by-step explanation:

Well, the first useful step to find the Standard Deviation is to organize it into a table. Let's insert the information. The data set ={9,12,14,21} Mean = 14 n= quantity of observations, in this case: 4

1) In the first column, the data set. In the second column, the squared difference of each number minus the mean. The sum of the second column will be plugged into the ∑ formula. (Check below)

2) Notice that in the second row, where x value is 9. (x-xbar)²= (9-14)². Yuri has made that mistake, and He compromised all the calculations.

KATRIN_1 [288]2 years ago
4 0

Answer:

Option B.

Step-by-step explanation:

Consider the below figure attached with this question.

Formula for standard deviation of a sample:

s=\sqrt{\dfrac{\sum (x-\overline{x})^2}{n-1}}

where, n is sample size and \overline{x} is sample mean.

The sample data set is 12, 14, 9, and 21.

The mean is 14.

So, the sample standard deviation is

s=\sqrt{\dfrac{(12-14)^2+(14-14)^2+(9-14)^2+(21-14)^2}{4-1}}

According to Yuri,

s=\sqrt{\dfrac{(12-14)^2+(14-14)^2+(9-14)^2+(21-14)^2}{4}}

Yuri divides the sum of square of difference between each data point and the mean by n instead of n -1.

Therefore, the correct option is B.

You might be interested in
Find [g o f](x)=5x-5,g(x)=3x-2
wariber [46]

Answer:

→f(x) = 5x - 5 \\→g(x) = 3x - 2 \\ [gof](x) = g(f(x))  = 3(5x - 5) - 2 \\ [gof](x) = 15x - 15 - 2 = 15x - 17 \\  \boxed{[gof](x) = 15x - 17}✓

  • <u>[gof](x) = 15x - 17</u> is the right answer.
7 0
2 years ago
Simplify the expression <br><br> 6 − 2 x + 5 + 4 x
Snezhnost [94]

Answer: 2x+11

Step-by-step explanation: hope this helps!

4 0
2 years ago
Read 2 more answers
A square pyramid is shown below:
GREYUIT [131]

Answer:

I do not see the picture, but if the following measurements are correct, then you have your answer!

The sides of the square base are labeled 0.9 foot. The height of one of the triangular sides is labeled 4 feet

Step-by-step explanation:

  1. 8.01 ft^{2} or 8.01 square feet
3 0
2 years ago
Read 2 more answers
a total of 32 students have entered a spelling contest there are 6 medals for first through sixth place that will be awarded in
lana [24]
Here the order matters (the medal of the 1st is different from the medal of the 2nd, etc.)
So it's a permutation (arrangement) of 6 chosen among 31:

 ³²P₆ = (n!)/(n-r)! = 32!/26! = 652,458,240

Another method:
the 1st medal could be won by 32
the  2nd medal could be won by 31 .
the  3dd medal could be won by 30
.etc. etc.
the  6th medal could be won by 27
.
Then the number of possibilities = 32x31x30x29x28x27 =652,458,240
6 0
3 years ago
What is the surface area of a cylinder with a radius of 5 ft and a height of 2 ft?
icang [17]
\bf \textit{total surface area of a cylinder}\\\\&#10;SA=2\pi r(h+r)~~&#10;\begin{cases}&#10;r=radius\\&#10;h=height\\&#10;-----\\&#10;r=5\\&#10;h=2&#10;\end{cases}\implies SA=2\pi (5)(2+5)&#10;\\\\\\&#10;SA=10\pi (7)\implies SA=70\pi
7 0
2 years ago
Other questions:
  • Find the surface area of the composite solid. round the answer to the nearest hundredth.
    7·1 answer
  • Suppose the population ofthe united states is about 230 million.Is this number closer to ten to the seventh power or ten to the
    9·1 answer
  • Translate the statement below. "One less than twice a number.."​
    10·2 answers
  • Could someone help me please
    12·1 answer
  • Can you help me understand this question? And what are they looking for? I really need help please...
    13·1 answer
  • Solve the equation. 0.3b = 8.1
    14·1 answer
  • If the radius of the circle is decreased by a factor of One-third, what happens to the circumference?
    6·2 answers
  • The system has......
    6·2 answers
  • Help me with this assignment problem​
    13·2 answers
  • What is the length of the side a ?<br><br> A=
    8·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!