Math Problem Statement

It appears that there is an outlier in the data set: {11, 10.7, 22, 101, 37, 13.7, 54, 13, 21, 11.9}. Is the statement 'There is an outlier' true?

Solution

The data set provided in the image is:

{11,10.7,22,101,37,13.7,54,13,21,11.9}\{11, 10.7, 22, 101, 37, 13.7, 54, 13, 21, 11.9\}

The question asks if there is an outlier in the data set.

To determine if there is an outlier, we can apply common methods such as calculating the Interquartile Range (IQR) or the z-score.

Steps for detecting outliers using the IQR method:

  1. Arrange the data in ascending order:
    10.7,11,11.9,13,13.7,21,22,37,54,10110.7, 11, 11.9, 13, 13.7, 21, 22, 37, 54, 101

  2. Find the median (middle value):

    • For 10 data points, the median is the average of the 5th and 6th values: 13.7+212=17.35\frac{13.7 + 21}{2} = 17.35 So, the median is 17.35.
  3. Find Q1 (First Quartile): The median of the lower half (first 5 values): Q1=median of {10.7,11,11.9,13,13.7}=11.9Q1 = \text{median of } \{10.7, 11, 11.9, 13, 13.7\} = 11.9

  4. Find Q3 (Third Quartile): The median of the upper half (last 5 values): Q3=median of {22,37,54,101}=37Q3 = \text{median of } \{22, 37, 54, 101\} = 37

  5. Calculate the IQR: IQR=Q3Q1=3711.9=25.1IQR = Q3 - Q1 = 37 - 11.9 = 25.1

  6. Determine the lower and upper bounds for detecting outliers:

    • Lower bound: Q11.5×IQR=11.91.5×25.1=11.937.65=25.75Q1 - 1.5 \times IQR = 11.9 - 1.5 \times 25.1 = 11.9 - 37.65 = -25.75
    • Upper bound: Q3+1.5×IQR=37+1.5×25.1=37+37.65=74.65Q3 + 1.5 \times IQR = 37 + 1.5 \times 25.1 = 37 + 37.65 = 74.65

Any value outside the range (25.75,74.65)(-25.75, 74.65) would be considered an outlier.

Conclusion:

The value 101 exceeds the upper bound of 74.65, which indicates that 101 is an outlier.

Thus, the statement "It appears that there is an outlier in the data set" is True.

Would you like further clarification or details?

Here are some related questions:

  1. How can we detect outliers using the z-score method?
  2. What are some common causes of outliers in data sets?
  3. How does removing outliers affect data analysis?
  4. What are the implications of an outlier in statistical modeling?
  5. How do outliers affect the mean and standard deviation?

Tip: When detecting outliers, always ensure that the method used (like IQR or z-score) suits the nature of the data set to avoid misinterpretations.

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Math Problem Analysis

Mathematical Concepts

Outliers
Descriptive Statistics
Interquartile Range (IQR)

Formulas

IQR = Q3 - Q1
Lower bound = Q1 - 1.5 * IQR
Upper bound = Q3 + 1.5 * IQR

Theorems

Interquartile Range (IQR) Outlier Detection Method

Suitable Grade Level

Grades 8-10