Biotech

• Frequency Distribution is a collection of observations produced by sorting them into classes and showing their frequency (or numbers) of occurrences in each Class.
• Ungrouped Frequency Distribution classifies a given data set (usually n<30) under specific category or class
• Ungrouped Frequency Distribution - Frequencies of each data is treated as individual data points or as discrete data
• Grouped Frequency Distribution is having an interval or ratio-level data, and beyond a sample size of 30
• Grouped Frequency Distribution - Frequencies of each data point are clustered in a specific class interval
• The three types of Frequency Distribution are Categorical, Ungrouped, and Grouped
• Categorical is used for data that can be placed in specific categories, such as nominal, or ordinal level data
• Lower class limit is the smallest value that can be included in the class
• Upper class limit is the largest value that can be included in the class
• Class boundaries are used to separate the classes so that there are no gaps in the frequency distribution
• Class marks are the midpoints of the classes
• Class width is the difference between two consecutive lower limits
• Cumulative frequency are classes that increases order, and is the sum of the frequencies for that class and all previous classes
• Frequency Table Procedures: Step 1 - Arrange the scores from lowest to highest
• Frequency Table Procedures: Step 2 - Determine the range
• Frequency Table Procedures: Step 3 - Compute the number of classes
• The Sturge rule is a rule for determining the desirable number of groups into which a distribution of observations should be classified
• The N in 1 + 3.322 log N is the number of observations
• The number of groups or classes in the Sturge rule is 1 + 3.322 log N
• Frequency Table Procedures: Step 4 - Find the class width
• Frequency Table Procedures: Step 5 - Select as a starting point, either the lowest score or the lower class limits. Add to the class width to the starting point to get the second lower class limit. Then enter the upper class limit.
• Frequency Table Procedures: Step 6 - Find the boundaries by subtracting 0.5 from each lower class limit and adding 0.5 to upper class limit
• Frequency Table Procedures: Step 7 - Tally the frequency of each class
• Frequency Table Procedures: Determine the class mark for each class interval