Fill in the blank: Primary data are collected for the first time for a specific purpose, while ___ data are those that have been previously collected by someone else.

Secondary

What is the difference between direct personal observation and indirect oral investigation in data collection methods?

Direct observation collects firsthand data.

• Observations are conducted in real-time.

• Indirect relies on others' insights.

• Multiple perspectives enhance validity.

True or False: Cumulative frequency distribution is used to show the frequency of values that equal or exceed a certain class boundary.

True

What are the two types of classification of data based on attributes?

Simple classification, which considers one attribute, and manifold classification, which accounts for multiple attributes simultaneously.

What is a histogram, and how is it constructed?

Histogram Graphs Frequency Distribution

• Visualizes data distribution clearly.

• Height shows frequency of values.

• Width represents data class intervals.

Fill in the blank: In a frequency polygon, the frequencies are plotted against the ___ of the respective classes.

Mid values

Describe the limitations of diagrammatic data presentation.

Diagrammatic data has limitations.

• Can provide vague ideas.

• Limits detailed information.

• May lead to misinterpretation.

What distinguishes primary data from secondary data in statistical analysis?

Primary data is original data.

• Primary data is firsthand.

• Secondary data is pre-existing.

• Purpose varies for each data type.

True or False: The class frequency refers to the total number of observations in all class intervals combined.

False; class frequency refers to the number of observations within a specific class interval.

What is an ogive, and how does it differ from a frequency polygon?

An ogive shows cumulative frequencies.

• Cumulative frequencies illustrated.

• Uses class boundaries for plotting.

• Differs from frequency polygons.

What are the main components of a frequency distribution table?

Class intervals, class frequencies, total frequency, class limits, and class boundaries.

Fill in the blank: The ___ of a class interval is calculated by subtracting the lower class boundary from the upper class boundary.

Width