presentation of quantitative data

• bar chart are when categories are placed along the x-axis and frequency on the y-axis (or other way). The height of each column represents the frequency of that iteam
• histograms are when bars touch each other and dat os continuous rather than discrete
• scattergrams are used for correlational analysis. Each dot represents one pair of related data. Illustrates strength and direction of correlation. The data on both axes must be continuous
• normal distribution is symmetrical, bell shaped curve. Most items are in the middle area of the curve with very few at the extreme ends
• skewed distributions are distributions that lean to one side or the other because most items are either at the lower or upper end of the distribution
• negative skew is when most of the distribution is concentrated towards the right of the graph, resulting in a long tail on the left
• positive skew is when most of the distribution is concentrated towards the left of the graph, resulting in a long tail on the right