Nt1310 Unit 1 Data Analysis Paper

Step 2. Draw the x and y axes. Label the x and y axes with the midpoint of each class and frequencies, respectively.
Step 3. Plot the points and connect adjacent points with line segments. Draw a line back to the x axis at the beginning and end of the graph. Be sure to use the same distance that the previous and next midpoints would be located.

You may also use Microsoft excel in constructing a frequency polygon. Here are the steps:
1. Input the midpoints in column A, and the frequencies in column B. (Use row 2 onwards for both columns)
2. In row 1, add the class width to the largest midpoint and indicate 0 frequency, for columns A and B, respectively.
3. In the row after the lowest midpoint, subtract the class width to the lowest midpoint and indicate 0 frequency,

In most cases, classes with extreme values and gaps in the distribution entails important information. Also, readers can make comparisons among the different data sets. In addition, it also facilitates computational procedure for other statistical measures (discussed in the succeeding lessons).
Example 5 – 4: Using the frequency distribution in example 5 -1,

Answer the following questions:
1. What are the lowest and highest scores obtained by the students in the Philippine History exam?
2. What percent of the students obtained a score within 50 – 59?
3. How many students obtained a score lower than 60?
4. If the passing score is 50, what percentage of the students passed the Philippine history exam?

Answers:
1. The lowest score is 30 and the highest score is 79.
2. 30% of the students obtained a score within 50 – 59.
3. 19 students scored lower than 60.
4. 66.67% passed the Philippine History exam.

Practice Your Skill 5.1
1. The data set shown below represents the average monthly electricity consumption (in kwh) of 30