Chapter 2
Frequency Table - correct answer ✔A frequency table partitions data into
classes or intervals of equal width and shows how many data values are in
each class. The classes or intervals are constructed so that each data value
falls into exactly one class
How to find the class width - correct answer ✔(Largest - smallest)/desired
number of classes
increase the computed value to the next highest whole number (even if
calculation results in a whole number)
*5 to 15 classes are usually used*
Lower Class Limit & Higher Class Limit - correct answer ✔The lower class
limit is the lowest data value that can fit in a class. The upper class limit is the
highest data value that can fit in a class. The class width is the difference
between the lower class limit of one class and the lower class limit of the next
class.
How to Tally Data/Class Frequency - correct answer ✔Tallying data is a
method of counting data values that fall into a particular class or category.
1) To tally data into classes of a frequency table, examine each data value.
2) Determine which class contains the data value and make a tally mark or
vertical stroke (|) beside that class. For ease of counting, each fifth tally mark
of a class is placed diagonally across the prior four marks (||||). The class
frequency for a class is the number of tally marks corresponding to that class.
Midpoint - correct answer ✔(Lower class limit + upper class limit)/2
, How to find class boundaries (integer data) - correct answer ✔To find upper
class boundaries, add 0.5 unit to the upper class limits
To find lower class boundaries, subtract 0.5 unit from the lower class limits.
Relative Frequency - correct answer ✔The relative frequency of a class is
the proportion of all data values that fall into that class
Divide the class frequency by the total of all frequencies n (sample size)
F/N
The total of relative frequencies should be 1
How to make a frequency table - correct answer ✔1. Determine the number
of classes and the corresponding class width.
2. Create the distinct classes. We use the convention that the lower class limit
of the first class is the smallest data value. Add the class width to this number
to get the lower class limit of the next class.
3. Fill in upper class limits to create distinct classes that accommodate all
possible data values from the data set.
4. Tally the data into classes. Each data value should fall into exactly one
class. Total the tallies to obtain each class frequency.
5. Compute the midpoint (class mark) for each class.
6. Determine the class boundaries.
Frequency Table - correct answer ✔A frequency table partitions data into
classes or intervals of equal width and shows how many data values are in
each class. The classes or intervals are constructed so that each data value
falls into exactly one class
How to find the class width - correct answer ✔(Largest - smallest)/desired
number of classes
increase the computed value to the next highest whole number (even if
calculation results in a whole number)
*5 to 15 classes are usually used*
Lower Class Limit & Higher Class Limit - correct answer ✔The lower class
limit is the lowest data value that can fit in a class. The upper class limit is the
highest data value that can fit in a class. The class width is the difference
between the lower class limit of one class and the lower class limit of the next
class.
How to Tally Data/Class Frequency - correct answer ✔Tallying data is a
method of counting data values that fall into a particular class or category.
1) To tally data into classes of a frequency table, examine each data value.
2) Determine which class contains the data value and make a tally mark or
vertical stroke (|) beside that class. For ease of counting, each fifth tally mark
of a class is placed diagonally across the prior four marks (||||). The class
frequency for a class is the number of tally marks corresponding to that class.
Midpoint - correct answer ✔(Lower class limit + upper class limit)/2
, How to find class boundaries (integer data) - correct answer ✔To find upper
class boundaries, add 0.5 unit to the upper class limits
To find lower class boundaries, subtract 0.5 unit from the lower class limits.
Relative Frequency - correct answer ✔The relative frequency of a class is
the proportion of all data values that fall into that class
Divide the class frequency by the total of all frequencies n (sample size)
F/N
The total of relative frequencies should be 1
How to make a frequency table - correct answer ✔1. Determine the number
of classes and the corresponding class width.
2. Create the distinct classes. We use the convention that the lower class limit
of the first class is the smallest data value. Add the class width to this number
to get the lower class limit of the next class.
3. Fill in upper class limits to create distinct classes that accommodate all
possible data values from the data set.
4. Tally the data into classes. Each data value should fall into exactly one
class. Total the tallies to obtain each class frequency.
5. Compute the midpoint (class mark) for each class.
6. Determine the class boundaries.
