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Consider the following two data sets. \(\begin{array}{llllrl}\text { Data Set I: } & 12 & 25 & 37 & 8 & 41 \\ \text { Data Set II: } & 19 & 32 & 44 & 15 & 48\end{array}\) Notice that each value of the second data set is obtained by adding 7 to the corresponding value of the first data set. Calculate the mean for each of these two data sets. Comment on the relationship between the two means.

Short Answer

Expert verified
The mean of data set I is \(24.6\) and the mean of data set II is \(31.6\). The mean of data set II is \(7\) units greater than data set I, showing that adding a constant to every number in a data set increases the mean by that same constant.

Step by step solution

01

Calculating the Mean for Data Set I

Firstly, calculate the mean of data set I. The mean, or average, is calculated by summing all the values in the data set and then dividing by the count of the values in the data set. For data set I, add the numbers \(12, 25, 37, 8, 41\), then divide the sum by \(5\) (the count of the numbers).
02

Calculating the Mean for Data Set II

Now, calculate the mean of data set II. Again, add up all the numbers in the set (\(19, 32, 44, 15, 48\)) and then divide by \(5\) (the count of the numbers in the set).
03

Comparing the Means of the Two Data Sets

Finally, it's time to compare the mean of data set I and the mean of data set II. You should observe that the mean of the second set is 7 units greater than the mean of the first set, reflecting the fact that each number in the second set was obtained by adding 7 to the corresponding number in the first set. This concludes that adding a constant to every number in a data set will increase the mean of that data set by that same constant.

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Key Concepts

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

Understanding Data Sets Comparison
Comparing data sets is an essential aspect of data analysis. It allows us to evaluate different data properties like mean, median, mode, and range, providing insights into the similarities and differences between two or more sets of data. In the context of mean calculation, comparing data sets can unveil how a change in data points affects the overall average value.

For instance, in the given exercise, two data sets are examined. Data Set I includes the values \(12, 25, 37, 8, \) and \(41\), while Data Set II consists of \(19, 32, 44, 15, \) and \(48\). Although these sets may seem different at a glance, a closer examination reveals that each number in Data Set II is merely Data Set I's corresponding number increased by 7. Such systematic differences can simplify the analysis of means and other statistical measures.

Bear in mind when comparing data sets, it's crucial to evaluate both their context and content. Understanding what each data set represents can often provide insights beyond simple numerical differences.
Adding a Constant to a Data Set
When a constant is added to each element of a data set, some properties of the data set change while others remain unaffected. This operation is fundamental in statistics and offers a simplification when analyzing how transformations affect statistical measures.

In the exercise provided, when \(7\) is added to each number in Data Set I to form Data Set II, we observe a notable effect: the mean of the data set is directly influenced by the constant addition. Such an operation is termed a linear transformation and is significant in understanding how data alterations can systemically affect a dataset's mean.

It's important to note that while adding a constant affects the mean, other measures like the variance and standard deviation remain unchanged by such a transformation, as the data spread remains consistent. This can be useful for statistical manipulation and presentations, preserving specific properties for analytical purposes.
Conducting a Mean Difference Analysis
Mean difference analysis is an approach to explore and interpret how the means of different data sets can signal changes or relationships between them. This type of analysis often follows from basic mean calculations, serving both practical and theoretical purposes in statistics.

In our example, after calculating the mean of both data sets, we see that the mean of Data Set II exceeds that of Data Set I by \(7\), precisely matching the constant added to produce Data Set II from I. This illustrates the straightforward relationship between adding a constant to data and a corresponding shift in mean.

Understanding these principles aids in predicting the impact of data transformations, which is essential in fields like economics, psychology, and other disciplines relying on quantitative data. Recognizing how and why the mean shifts with data transformations allows for deeper analysis and meaningful conclusions in various scenarios.

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