Math Problem Statement

  1. A tutor’s records show that the numbers of students present during the last ten classes are as follows: 16, 19, 20, 12, 17, 18, 18, 16, 15 and 18. Organise the data into a relative frequency histogram using classes starting from 12 to 14.

Solution

To create a relative frequency histogram, we first organize the data into classes and calculate the relative frequency for each class. Here's a step-by-step approach:


Step 1: Organize the data into classes

The classes, as specified, start from 12 to 14, and we'll assume each class width is 2. The classes are:

  1. 12–14
  2. 15–17
  3. 18–20

Step 2: Tally the data

Count how many numbers from the dataset fall into each class:

  • Dataset: 16,19,20,12,17,18,18,16,15,1816, 19, 20, 12, 17, 18, 18, 16, 15, 18
    1. 12–14: 1212 → 1 number
    2. 15–17: 16,17,16,1516, 17, 16, 15 → 4 numbers
    3. 18–20: 19,20,18,18,1819, 20, 18, 18, 18 → 5 numbers

Step 3: Calculate relative frequency

The relative frequency for each class is the ratio of the count in that class to the total number of data points.

  • Total number of data points = 1010
  • Relative frequencies:
    1. 12–14: 110=0.1\frac{1}{10} = 0.1
    2. 15–17: 410=0.4\frac{4}{10} = 0.4
    3. 18–20: 510=0.5\frac{5}{10} = 0.5

Step 4: Represent the data in a histogram

The histogram would show the classes on the x-axis and the relative frequencies on the y-axis. I'll create a visualization for this. matplotlib.pyplot as plt

Data for the histogram

classes = ["12-14", "15-17", "18-20"] relative_frequencies = [0.1, 0.4, 0.5]

Plotting the histogram

plt.bar(classes, relative_frequencies, color='blue', edgecolor='black')

Adding labels and title

plt.xlabel("Classes") plt.ylabel("Relative Frequency") plt.title("Relative Frequency Histogram")

Display the histogram

plt.show()Here is the relative frequency histogram. Each bar represents a class with its relative frequency:

  • 12–14: Relative frequency = 0.1
  • 15–17: Relative frequency = 0.4
  • 18–20: Relative frequency = 0.5

Would you like me to break down the calculation or further explain how histograms work?


Here are 5 questions to expand your understanding:

  1. How would the histogram change if more students were recorded in the next 10 classes?
  2. What is the difference between a relative frequency histogram and a frequency histogram?
  3. How do you determine the class width for a dataset?
  4. What are other types of graphs that can represent frequency data?
  5. How would the histogram look if there were an additional class, like 21–23?

Tip: Always verify that the total of the relative frequencies adds up to 1 (or very close due to rounding).

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Math Problem Analysis

Mathematical Concepts

Statistics
Data Organization
Relative Frequency Histogram

Formulas

Relative frequency = (Class frequency) / (Total number of data points)

Theorems

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Suitable Grade Level

Grades 8-10