Means, Modes, Median & More
Means - Averages
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Means are also known as averages.
Averages are useful way of splitting out figures. To work out an average we get the sum(total) of all values and divide it by how many numbers that exist. For example: 2, 8, 4, 10 is a set of numbers 2 + 8 + 4 + 10 = 24 There are a 4 numbers in this set 24/4 = 6 For today's activities we have three different types of times when it is useful to use averages. Instead of working it out the hard way we can use =average(). Fishing Bob and his mates go fishing every weekend. However Bob, Kate, Sarah and Steven do work around the boat and don't get as much time to fish. Whereas Hemi, Mikerea, Mary, Hank and Duncan fish 90% of the time. As they catch more fish they want to divide them up evenly so that everyone gets a fair amount |
Splitting the bill
8 friends have gone out for dinner and drinks. Rather then paying for their food individually they decide to split the bill. Work out how much everyone would pay at the table? Who gets the better deal Marist Girls Basketball Team
Due to an admin error Marist Girls were not able to play the first 4 games in the tournament. The officials said they would get the average amount of points for each of the rounds. |
Problems With Averages - Modes, Median, Upper Quartile, Lower Quartile
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Some statistics can often represent the data and can mislead or misinform people.
Think about the Marist Girls games, and the splitting the bill activity. In both those cases who wins? who loses? are they fair? is an average the best way to work out who should pay what? We have many other ways of working out statistics: Mode: A mode finds the most frequent value, for example what is the most frequent amount of skittles in a skittles bag? (if we open 100). =mode() Lower Quartile, Medium, Upper Quartiles. The medium finds the exact middle value. If there is no middle value then it find the average between the two middle values. The lower quartile and upper quartiles find the middle values between the medium. Task: Complete the skittles and house activity, Answer the question about which figure would be best to use in those situations. |
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Box and Whisker Diagrams
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Would it not be great if we could simply create a easy visual way to see the median, upper quartile and lower quartile all in one easy graph?
Well you are in luck there certainly is. Box and whisker graphs are the best way at showing this data at a glance. You can see all these figure and the distribution. To create one: 1.) Highlight the data 2.) Click insert graph 3.) Select Box & Whisker from all charts. Task: Create a box and whisker graph for: a.) The housing prices Excel sheet b.) The number of rooms in the housing prices c.) The total amount of skittles (new column needed) d.) The total expenditure in the Averages excel Splitting the bill activity. |
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Working out Percentages
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In order to work out percentages we take the part and then divide it by the whole
For example if I have 20 Xbox achievements out of 50 for "Halo Infinite" then I go: 20 / 50 = .4 .4*100 = 40 I have unlocked 40% of the achievements for Halo Infinite. In excel we don't * it by 100 we just hit the % button Task: Complete the working out percentages activity |
Why percentages?
For small numbers like 20 out of 50, there isn't an obvious reason to use percentages. However for large numbers such as 23943234 out of 603993243 percentages become important for humans to visualize data |
