Presentation of quantitative data

Question 1

When are bar chart?

Answer 1

• used with data in categories
• bars are seperate on bar charts to denote the seperate conditions

Question 2

When are histograms used?

Answer 2

• used when data is continuous
• the x axis is made of equal sized intervals
• bars touch eachother

Question 3

When are scattergrams used?

Answer 3

• correlations
• used to show a relationship between co - variables

Question 4

What are normal distributions?

Answer 4

• the mean, mode and median are call in the same midpoint of a curve
• tails of the curve never touch the x axis as extremes are always possible

Question 5

What are skewed distributions?

Answer 5

• Positive skew = distribution is concentrated to the left of a graph, a difficult test where everyone had poor marks
• mode is the highest point of the peak, median is next, and the mean is dragged towards the tail as extreme scores affect the mean.
• negative skew = distribution is concentrated to the right of a graph, an easy test where everyone had high marks
• mode is the highest point of the peak, median is next, and the mean is dragged towards the tail on the left as extreme scores affect the mean.

Question 6

Draw a negative and positive skew?