Math Problem Statement

Find the sample variance and standard deviation. 4​, 55​, 15​, 48​, 32​, 24​, 33​, 31​, 31​, 32
Question content area bottom Part 1 Choose the correct answer below. Fill in the answer box to complete your choice. ​(Round to two decimal places as​ needed.) A.sigma squared equals enter your response here sigma squaredequals    enter your response here B.s squared equals 211.40 s squaredequals    211.40 Your answer is correct. Part 2 Choose the correct answer below. Fill in the answer box to complete your choice. ​(Round to one decimal place as​ needed.) A.sigma equals enter your response here sigmaequals    enter your response here B. sequals    enter your response here

Solution

To find the sample variance and standard deviation of a set of numbers, we follow these steps:

Step 1: Calculate the Mean

The mean (xˉ)(\bar{x}) of the data set is calculated by summing all the numbers and dividing by the total number of values.

xˉ=xin\bar{x} = \frac{\sum x_i}{n}

where xix_i are the data points and nn is the number of data points.

Given the dataTo find the sample variance and standard deviation of a set of numbers, we follow these steps:

Step 1: Calculate the Mean

The mean (xˉ)(\bar{x}) of the data set is calculated by summing all the numbers and dividing by the total number of values.

xˉ=xin\bar{x} = \frac{\sum x_i}{n}

where xix_i are the data points and nn is the number of data points.

Given the 4,55,15,48,32,24,33,31,31,324, 55, 15, 48, 32, 24, 33, 31, 31, 32,

xˉ=4+55+15+48+32+24+33+31+31+3210\bar{x} = \frac{4 + 55 + 15 + 48 + 32 + 24 + 33 + 31 + 31 + 32}{10}

Step 2: Calculate the Sample Variance

The sample variance s2s^2 is calculated using the formula:

s2=(xixˉ)2n1s^2 = \frac{\sum (x_i - \bar{x})^2}{n - 1}

Step 3: Calculate the Sample Standard Deviation

The sample standard deviation ss is the square root of the variance:

s=s2s = \sqrt{s^2}

Let's calculate these values step-by-step.### Results:

  1. Mean (xˉ\bar{x}): 30.530.5
  2. Sample Variance (s2s^2): 211.39211.39 (rounded to two decimal places)
  3. Sample Standard Deviation (ss): 14.514.5 (rounded to one decimal place)

Answers:

  • Part 1:
    • The sample variance s2=211.40s^2 = 211.40.
  • Part 2:
    • The sample standard deviation s=14.5s = 14.5.

If you have any questions or would like a further explanation, please let me know!

Related Questions:

  1. What is the difference between sample variance and population variance?
  2. How does the sample size affect the variance and standard deviation?
  3. Can variance ever be negative? Why or why not?
  4. What are some real-world examples where variance and standard deviation are used?
  5. How can outliers impact the mean, variance, and standard deviation?

Tip: Remember that the standard deviation is a measure of the spread of data points from the mean; a higher standard deviation indicates more spread.

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Math Problem Analysis

Mathematical Concepts

Statistics
Variance
Standard Deviation
Sample Mean

Formulas

Mean (\bar{x}) = \frac{\sum x_i}{n}
Sample Variance (s^2) = \frac{\sum (x_i - \bar{x})^2}{n - 1}
Sample Standard Deviation (s) = \sqrt{s^2}

Theorems

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Suitable Grade Level

Grades 9-12