In the SEHS course there will be many occasions where we are studying data. It is important that all students are familiar with, and understand, and are able to:
• perform the basic arithmetic functions: addition, subtraction, multiplication and division
• carry out simple calculations involving means, decimals, fractions, percentages, ratios, approximations, reciprocals and scaling
• use standard (or Scientific) notation (for example, 3.6 × 10
6
)
• use direct and inverse proportion
• represent and interpret frequency data in the form of bar charts, column graphs and histograms, and interpret pie charts
• determine the mode and median of a set of data
• plot and interpret graphs (with suitable scales and axes) involving two variables that show linear or non-linear relationships
• plot and interpret scattergrams to identify a correlation between two variables, and appreciate that the existence of a correlation does not establish a causal relationship
(a correlation is a depiction of the strength of a linear relationship)
• make approximations of numerical expressions
• recognize and use the relationships between length, surface area and volume.
Example: looking at a cube….
Length = 4 cm, Surface area one side is 16 cm, Volume is 64 cm
But if cube size is doubled (8 cm in length),
Length = 8 cm, Surface area is 64, and Volume is 512 cm

Means, Modes, Standard Deviation, and the Co-efficient of Variation
Quick Exercise:
How many games are the Twins going to win next year?
How many games are the Vikings going to win this season?
You would expect the Standard Deviation of the guesses of the Twin’s success would be greater than that of the Viking’s success…….why?
Exercise 1: ( Students work in Pre-Arranged Squads of 4 )
(Photocopied box scores of American League Baseball Teams are distributed to Students)
Find Mean batting average of each team in the American League
Calculate from that the Mean batting Average of all Players in the
American League
Find the Mode of the Batting averages for all the American league
Baseball Players
Plot the score of the Mean batting averages of all teams in the America
League onto a graph.
Calculate the STANDARD DEVIATION (average distance from the mean) of this set of data. Use graphic display calculator.
What are the “Error Bars” indicating (the amount of minimum and
Maximum distance from the Standard Deviation)
What is the Co-Efficient of Variation between the team with the closest
Mean to the Standard Deviation and the Team with the Farthest Mean from the Standard Deviation? Express as a %.
( eg. If Mean is 100 and the Standard Deviation is 5, then the Coefficient of Variation = 5%
But if Mean is 50 and the Standard Deviation is 5, then the Coefficient of Variation = 10%)

Exercise 2: The relationship between height of players in the Mens’ and
Womens’ NBA and their success on the court.
Distribute Copies of either Mens or Womens NBS Rosters with the heights of the players noted.
Find the Mean height of each Team
Find the Mean height of the League.
Find the Standard Deviation of the heights of players in the League
Plot Mean height against the Position in the League last year
Note any Correlations found.
Which has the Largest Standard Deviation - Mens NBA of Womens
NBA?
Compare discuss the Standard Deviation, Average mean and position in the League between Mens and Womens Leagues.