Maths

• What can a bar chart be used for?

  Nominal data & not continuous
• What can a line graph be used for?

  Continuous data
• What can a scatter diagram be used for?

  Correlational analysis
• What is the normal distribution?

  Bell-shaped curve. Predicted distribution when considering an equally likely set of results. Mean, median & mode all in exact mid-point. Distribution symmetrical around this mid-point. Dispersion of scores/measurements either side of mid-point is consistent & expressed as standard deviations.
• What is a skewed distribution?

  In some populations scores not distributed equally around mean. Can be positive or negative.
• Positive skewed distribution:


  Mean higher than median & mode. Extreme values has effect on mean.
• Negative skewed distribution:


  Mean lower than median & mode. E.g, marks plotted for exam that had very easy questions so most got high score.