Final answer:
The key functions of a custom summary formula field in a report are Count, Sum, and Average, which are used to aggregate and analyze data. While not a direct answer for calculating sample mean, sample standard deviation, or percentages, they represent similar basic statistical tools that are utilized in report analysis and data manipulation.
Step-by-step explanation:
Some key functions of a custom summary formula field in a report include Count, Sum, and Average. These functions allow users to calculate totals, averages, and counts of various data points within a report. For example, the Count function tallies how many times a particular value occurs, the Sum function adds up numerical values, and the Average function computes the mean of a series of numbers.
In the context of a mathematics question about calculating cumulative frequency, sample mean, sample standard deviation, and percentage of estimates at or below a certain value, it's important to use different mathematical methods:
- Complete the cumulative frequency column by adding the frequency of the current row to the sum of the frequencies of all previous rows.
- Calculate the sample mean by summing all the observations and dividing by the number of observations.
- Calculate the sample standard deviation by using the formula that measures the amount of variation or dispersion from the mean.
- To determine the percent of estimates that fall at or below four, divide the cumulative frequency of the data at or below four by the total number of observations and multiply by 100 to get a percentage.