3 Flashcards
What is a frequency distribution
A table, or a chart that shows how often certain values or categories occur in a data set.
What is meant by relative frequency
The percent of time something comes up(frequency/total)
What is meant by cumulative frequency
Add up the frequency as you go… Suppose you are selling 25 pieces of candy. You sell 10 the first hour, 5 the second hour, and 3 the third hour and 7 the last hour. The cumulative frequency would be 10, 15, 18, 25
What is meant by cumulative relative frequency
It is the ADDed up Percentages Suppose you are selling 25 pieces of candy. You sell 10 the first hour, 5 the second hour, and 3 the third hour and 7 the last hour. The cumulative frequency would be 10, 15, 18, 25… change these to percentage by dividing each by 25 and you get .4, .6, .64, 1.00
How do you find relative frequency
Just divide frequency by TOTAL
What is the difference between a bar chart and a histogram
Bar chart are for categorical data(bars do not touch) and histograms are for quantitative data(bars touch)
What does a measure of “central tendency” try to tell us about
Meant to convey the “general idea” of where most data values lie
What is the mean
The old average we used to calculate. It is the balancing point of the histogram
What is the difference between populate mean and sample mean
Population mean is the mean of a population, it is a parameter, sample mean is the mean of a sample, it is a statistic. We take sample mean to make inferences about population means… We take statistics to make inferences about parameters.
What symbols do we use for population mean and sample mean
mu mor population mean( parameter), x-bar for sample mean(statistic)
How can you think about the mean and median to remember the diff
Mean is balancing point of histogram, median splits the area of the histogram in half
What is a frequency
How often something comes up
