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How large is a wolf pack? The following information is from a random sample of winter wolf packs in regions of Alaska, Minnesota, Michigan, Wisconsin, Canada, and Finland (Source: The Wolf, by L. D. Mech, University of Minnesota Press). Winter pack size: \(\begin{array}{rrrrrrrrr}13 & 10 & 7 & 5 & 7 & 7 & 2 & 4 & 3 \\ 2 & 3 & 15 & 4 & 4 & 2 & 8 & 7 & 8\end{array}\) Compute the mean, median, and mode for the size of winter wolf packs.

Short Answer

Expert verified
Mean: \(6.17\), Median: 6, Mode: 7.

Step by step solution

01

Arrange the Data in Order

First, arrange the pack sizes in ascending order to make it easier to calculate the median and find the mode. The ordered sizes are: 2, 2, 2, 3, 3, 4, 4, 4, 5, 7, 7, 7, 7, 8, 8, 10, 13, 15.
02

Calculate the Mean

Add all the pack sizes together and then divide by the number of values. The sum is 111 and there are 18 values. So, the mean is \( \frac{111}{18} \approx 6.17 \).
03

Find the Median

The median is the middle value in the ordered list. Since there are 18 entries, the median is the average of the 9th and 10th values. The 9th value is 5 and the 10th value is 7, so the median is \( \frac{5 + 7}{2} = 6 \).
04

Identify the Mode

The mode is the number that appears most frequently. In this case, the number 7 appears four times, which is more frequent than any other number. Therefore, the mode is 7.

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Understanding Mean
The mean, also commonly referred to as the average, is a measure of central tendency that sums up an entire dataset by dividing the total sum of all values by the number of values present. This straightforward calculation helps us understand the general size or magnitude of the dataset's elements.
To calculate the mean:
  • Add up all the numbers in the dataset.
  • Divide the total by the number of values.
For the winter wolf pack sizes:
  • The total of all sizes is 111 when you add them together.
  • There are 18 unique wolf pack sizes.
Thus, the mean wolf pack size is \( \frac{111}{18} \approx 6.17 \).
This means that, on average, a winter wolf pack consists of approximately 6.17 wolves. The mean provides us a way to think about the typical size of these packs across different regions, although it should be noted that real wolf packs are composed of whole numbers so an average like 6.17 gives a general idea only.
Exploring Median
The median is another measure of central tendency that identifies the middle value in a list once it has been sorted in order. This gives us an idea of the central point of the dataset when it's laid out from smallest to largest. In scenarios with outliers or skewed data, the median is often a better representation of central tendency than the mean.
To find the median:
  • Arrange the data in ascending order.
  • Identify the middle value. If there is an odd number of data points, it's simply the central number. If even, it's the average of the two middle numbers.
For the winter wolf pack sizes, which are 18 in total:
  • We arranged them as: 2, 2, 2, 3, 3, 4, 4, 4, 5, 7, 7, 7, 7, 8, 8, 10, 13, 15.
  • The median position is between the 9th and 10th values.
  • The 9th value is 5, and the 10th is 7, so the median is \( \frac{5 + 7}{2} = 6 \).
This shows that the median wolf pack size is 6, which means that half of the wolf packs are larger than this size and half are smaller, providing a central point for the dataset.
Defining Mode
The mode is a measure of central tendency that identifies the most frequently occurring value within a dataset. Unlike the mean or median, the mode can be applied to both numerical and categorical data, making it versatile for various applications.
To determine the mode:
  • Identify which value appears most frequently in your dataset.
  • If multiple values appear with the same maximum frequency, the dataset is multimodal and all are modes.
In the wolf pack data:
  • The arranged wolf pack sizes are: 2, 2, 2, 3, 3, 4, 4, 4, 5, 7, 7, 7, 7, 8, 8, 10, 13, 15.
  • Here, the number 7 occurs four times, more than any other value.
Thus, the mode of this dataset is 7, indicating that 7 is the most common size for a winter wolf pack in the given regions.

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Most popular questions from this chapter

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