Kōkiri Learn

Week 3 of 4

Summarise, check and test chance

  1. 1
  2. 2
  3. 3
  4. 4

Session 1 · SOLVE: Link Ideas

Averages and spread

  1. 15 minMean, median, mode and range: work through the pocket-money example together, then see how one big value drags the mean but not the median.
  2. 20 minCalculate all four for your data. Check each one with an estimate first: does the mean sit somewhere in the middle of the dot plot?
  3. 15 minDecide which average best describes your data and write one sentence saying why.

Session 2 · SOLVE: Verify

Is our conclusion fair?

  1. 10 minSwap graphs and summaries with another group. Check one calculation each.
  2. 15 minOutlier hunt: find any values far from the rest. Mistake or real? A real outlier stays in, and you explain it.
  3. 15 minCompare the result with the prediction on the board. Were you right, partly right or wrong? What surprised you?
  4. 10 minLimitations: was the sample big enough and fair? Who is missing from it? Tohu asks one question about your conclusion.

Session 3 · SOLVE: Verify

Chance experiment

  1. 10 minPredict: if we pick one person (or one day, or one bird) at random from our data, what is the chance it is in the biggest group? Write it as a fraction, decimal and percentage.
  2. 20 minTest it: put one card per data value in a bag and draw with replacement at least 30 times. Tally the results and calculate the experimental probability.
  3. 15 minPool every group's trials. What happens to the experimental probability as the number of trials grows?
  4. 5 minWrite one sentence explaining the difference between your 30-trial result and the pooled result.

Getting started

Use a spreadsheet to calculate the mean, then find the median by sorting the column.

Stretch

Show, with numbers, how removing one outlier changes the mean and the range but hardly moves the median.

Checkpoint

Correct summary values, a reasoned choice of average, and one named limitation of the data.

Activities for this week

Useful this week