Math Problem Statement

Here is the list of heights in cm for a group of 20 people: 154, 147, 145, 160, 166, 178, 151, 176, 179, 161, 180, 173, 153, 155, 155, 162, 147, 147, 180. 1. Create a table by grouping the heights into 5 classes and calculate the frequency and percentage for each class. 2. Draw a histogram showing the frequencies.

Solution

Let's solve the problem from the image you've provided.

Problem Breakdown:

  1. Data: Heights of 20 people (in cm):

    154, 147, 145, 160, 166, 178, 151, 176, 179, 161, 180, 173, 153, 155, 155, 162, 147, 147, 180
    
  2. Task 1:

    • Group the heights into 5 classes.
    • Calculate the frequency for each class and provide the percentage for each (rounded to two decimal places).
  3. Task 2:

    • Draw a histogram showing the frequency of each class.

Step 1: Determine class intervals

We will divide the heights into 5 classes. To do this, we need the range of the dataLet's solve the problem from the image you've provided.

Problem Breakdown:

  1. Data: Heights of 20 people (in cm):

    154, 147, 145, 160, 166, 178, 151, 176, 179, 161, 180, 173, 153, 155, 155, 162, 147, 147, 180
    
  2. Task 1:

    • Group the heights into 5 classes.
    • Calculate the frequency for each class and provide the percentage for each (rounded to two decimal places).
  3. Task 2:

    • Draw a histogram showing the frequency of each class.

Step 1: Determine class intervals

We will divide the heights into 5 classes. To do this, we need the range of the

  • Min height: 145 cm
  • Max height: 180 cm
  • Range: 180 - 145 = 35 cm

To divide this into 5 classes:

  • Class width = 35 / 5 = 7 cm

Thus, the class intervals will be:

  1. 145 cm – 151 cm
  2. 152 cm – 158 cm
  3. 159 cm – 165 cm
  4. 166 cm – 172 cm
  5. 173 cm – 180 cm

Step 2: Count the number of heights in each class (Effective frequency)

I will calculate the frequency distribution for each of the above classes.### Results:

  1. Class Intervals and Frequencies:
Class IntervalEffective FrequencyPercentage Frequency (%)
145 cm – 151 cm526.32%
152 cm – 158 cm421.05%
159 cm – 165 cm315.79%
166 cm – 172 cm15.26%
173 cm – 180 cm631.58%

Step 3: Histogram Plot

I'll now draw the histogram based on these class intervals and frequencies.It seems like I can't do more advanced data analysis right now. Please try again later.

In the meantime, you can manually plot the histogram using the class intervals and their corresponding frequencies from the table provided.

Do you have any other questions or need further clarification on this problem?

Here are 5 related questions:

  1. How would you calculate the mean height of the group?
  2. What is the cumulative frequency for the first two classes?
  3. How would you determine the median height from the data?
  4. Could you calculate the variance and standard deviation for these heights?
  5. How would you construct a cumulative frequency histogram for this data?

Tip: Always check your class intervals carefully when creating a frequency table to ensure they cover all data points without overlap.

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Math Problem Analysis

Mathematical Concepts

Statistics
Class Intervals
Frequency Distribution
Histogram

Formulas

Class Width = (Max Height - Min Height) / Number of Classes
Frequency Percentage = (Class Frequency / Total Frequency) * 100

Theorems

Fundamental Theorem of Arithmetic (for calculating intervals)
Basic principles of frequency distributions

Suitable Grade Level

Grade 10-12