14 - Presentation of Quantitative Data

Question 1

What data do you present using bar charts? What are its key features?

Answer 1

Nominal data

Height of each bar = frequency

Space between each bar represents lack of continuity

Question 2

What data do you present with histograms? What are its key features?

Answer 2

Ordinal / interval data

Area = proportional to frequencies presented

Y - axis starts at 0

No gaps between the bars

Question 3

What data do you present using line graphs? What are its key features?

Answer 3

Ordinal or interval data

Shows how something changes over time usually

Question 4

What do you present using scatter grams? What are is key features?

Answer 4

Depicts associations between co - variables

Closer to line of best fit = stronger correlation

Question 5

What are the key features of a normal distribution curve?

Answer 5

Bell shaped

Symmetrical

Mean, mode and median all on the same midpoint

Ends of curve never touch x axis ( more extreme scores always theoretically possible)

Question 6

Describe a positively skewed normal distribution curve

Answer 6

Data concentrated to the left

Mode is the highest peak
Median comes next
Mean dragged across to the right

Opposite for negative skew