Grouped Data Frequency Distributions

The salary ranges of a sample of Australian citizens are collected. One of the class intervals is from $80,000 - <$90,000.

The midpoint of the class interval is:

The heat times for the swimmers in a 100m freestyle competition are grouped in the adjacent frequency distribution table.

The number of swimmers in the competition was

• 1

• 5

• 11

• 24

The heat times for the swimmers in a 100m freestyle competition are grouped in the adjacent frequency distribution table.

The median class interval of the data is

• 50 - < 52 seconds

• 52 - < 54 seconds

• 54 - < 56 seconds

• 56 - < 58 seconds

The heat times for the swimmers in a 100m freestyle competition are grouped in the adjacent frequency distribution table.

The modal class interval of the data is

• 50 - < 52 seconds

• 52 - < 54 seconds

• 54 - < 56 seconds

• 56 - < 58 seconds

Advantages of converting raw data into grouped data can include:

• Producing more accurate statistics

• Enabling easier-to-read graphical representations of the data

• Allowing for more efficient estimation of statistics for large datasets

• Creating a greater amount of information for statistical analysis

A group of adults is surveyed on the number of hours of sleep which they had the night before.

An estimation of the mean for the data is

• 6.38 hours

• 7.00 hours

• 7.41 hours

• 25.23 hours

A group of adults is surveyed on the number of hours of sleep which they had the night before.

The grouped data median is

• 5.30 hours

• 5.91 hours

• 6.68 hours

• 7.75 hours

A group of adults is surveyed on the number of hours of sleep which they had the night before.

One adult says that they slept for five-and-a-half hours. This value doesn't fit neatly into any class interval because

• It is not possible to sleep for five-and-a-half hours

• "Hours slept" is a continuous variable, but the class intervals are set up for discrete data

• "Hours slept" is a categorical variable, but the class intervals are set up for numerical data

• "Hours slept" is a discrete variable, but the class intervals are set up for continuous data

Label the final column in the adjacent image

d

Mean

Cumulative Frequency

Standard Deviation

xf

Calculate the frequency of the 90 - 119 class interval.

• 1

• 2

• 3

• 4