Presentation and display of Quantitative data

Describe the bar chart

Used when data is divided into categories

Use space between bars, not related

Variable on the x-axis is continuous

Describe histograms

Bars touch, related

Width of bars can change

Frequency should be on y-axis and continue should be on x-axis

Describe scattergram

Used to look at relationship between two variables

Once score is plotted, it will give direction

What is normal distribution?

When most the scores will be on the mean

3 ways to tell if something is normal distribution

1. Calculate central tendency, see if the results are similar

2. Plot on histogram and see if it forms a bell-shaped curve

3. Examine visually. Look at data and see if scores are clustered around the mean

Describe negative skew

Tai is to the left, values are to the right

Mode needs to be more than mean

Describe positive skew

Tail is to the right, values to the left

Mode needs to be less than mean