At the start of the year I started using a service call unroll me with my gmail account. It allows you to wrap up regular or subscription emails into one daily email digest. It takes a number of months to setup the service to capture all your regular or subscription emails, but I have found it helpful in reducing the clutter in my email so worth the minimal effort.

I noticed – as you do when you’re a stats teacher – that the number of emails that are rolled up per day varies. I wondered if there was anything going on – any patterns, trends etc. –  so went back over the last couple of months and recorded how many emails were wrapped up per day.

So here’s a little challenge for your students 🙂

Using the data on the number of my emails wrapped per day for the last few months, can they predict how many of my emails will be wrapped up over the next four days (Tuesday), Wednesday, Thursday and Friday?

Here’s the data…….

Jump with the data into iNZight lite

Download the data as a CSV

Link for data:

Raw data as ordered counts (first count is a Monday)


Not sure how to get the students started?

Here are some ideas you could give to students:

  • Graph the data in Excel or another spreadsheet and used “your eyes” and/or a sketch to make the prediction
  • Import the data into iNZight (or equivalent) and try to use a time series model to make the predictions
  • Find the mean number of emails rolled up for each day of the week and use these to make the predictions
  • Use a probability distribution to model the number of emails rolled up each day and generate four random outcomes from this model to make the predictions

So how many emails did I get?

Move your mouse over the grey box below to see 🙂

Tuesday: 22

Wednesday: 29

Thursday: 30

Friday: 33