Java Code Example: Calculating Mean, Median, and Mode

📚 Quick Study Guide

• 🔢 Mean: The average of a dataset. Calculated by summing all values and dividing by the number of values. Formula: $\text{Mean} = \frac{\sum_{i=1}^{n} x_i}{n}$
• 📊 Median: The middle value in a sorted dataset. If there are an even number of values, it's the average of the two middle values.
• ⭐ Mode: The value that appears most frequently in a dataset. A dataset can have no mode, one mode, or multiple modes.
• 💻 Java Implementation: Using arrays or ArrayLists to store data, and loops or stream operations to calculate these measures.

Practice Quiz

1. Question 1: Which of the following is the correct formula for calculating the mean of a dataset?
   1. A. $\frac{\text{number of values}}{\text{sum of values}}$
   2. B. $\text{sum of values} \times \text{number of values}$
   3. C. $\frac{\sum_{i=1}^{n} x_i}{n}$
   4. D. $\sqrt{\sum_{i=1}^{n} x_i}$
2. Question 2: What does the median represent in a dataset?
   1. A. The most frequent value
   2. B. The average value
   3. C. The middle value when the data is sorted
   4. D. The sum of all values
3. Question 3: What does the mode represent in a dataset?
   1. A. The least frequent value
   2. B. The average value
   3. C. The middle value
   4. D. The most frequent value
4. Question 4: What should you do first when finding the median of a dataset?
   1. A. Find the mode
   2. B. Sort the dataset
   3. C. Calculate the mean
   4. D. Count the number of values
5. Question 5: In Java, which data structure is commonly used to store the dataset for calculating mean, median, and mode?
   1. A. HashMap
   2. B. LinkedList
   3. C. Array or ArrayList
   4. D. HashSet
6. Question 6: What happens if a dataset has two modes?
   1. A. The mean is the mode
   2. B. It is bimodal
   3. C. The median is the mode
   4. D. It has no mode
7. Question 7: Which of the following is the correct way to find the mean using Java streams?
   1. A. `Arrays.stream(data).average()`
   2. B. `Arrays.stream(data).median()`
   3. C. `Arrays.stream(data).mode()`
   4. D. `Arrays.stream(data).sum()`