Had several questions sent in over the last week or two. Haven’t had time to answer everyone yet, apologies! I thought I’d share some of the responses with you, since when one student has a question it’s more than likely someone else was wondering the same thing. These all relate to the core. Question: What [...]

Today I’m posting a quick video about how to do four median smoothing (with centring!) straight on to a time series graph. It can get a bit tricky with all the median points you need to draw on there so my number one tip for this would be use different colours; one for the first [...]

Following on from the previous tutorial on how to smooth time series data, this video runs through an example question covering all the steps to do with smoothing and using smoothed trend lines to make predictions. The question comes from the MathsWorld further mathematics textbook published by MacMillian (2005). Speaking of that textbook, it is [...]

Today’s tutorial is all about smoothing time series data. Learn how to smooth data using 3 point and 5 point smoothing, using either means or medians. I’ll show you how to apply median smoothing straight on to the graph. I’ll also run through smoothing with an even number of points (such as 4 point moving [...]

I’ve had a question sent in regarding applying a three median regression line to a time series plot. Applying regression to time series data is the same as applying regression to the other scatterplots and data sets we’ve looked at in the Core chapters, so you follow the same steps. This question is a bit [...]

Today’s tutorial is all about seasonal indices. The video covers how to calculate seasonal indices, how to deseasonalise data, how to convert between deseasonalised and actual data, how to find and plot trend lines, how to interpret deseasonalised trend lines, and then I’ve thrown in some past exam questions for good measure.

Giving numbers to these tutorials is doing my head in because I’ve gone out of order a bit now. This is technically tutorial #22, but I’ve skipped a bit of stuff on least squares regreesion, residuals and residual plots, and also data transformations that I’m planning to go back and fill in at some stage. [...]

Today we ticked over 100 votes in the poll regarding which modules your schools are doing!! I’m really excited, proud and humbled to see that over a hundred further maths students (and some of their teachers) have logged on to this site, and liked it enough to have their say. It was a close run [...]

I was emailed a question recently by a student who wanted to know more about the difference between independent/dependent variables. Having watched the tutorial on independent and dependent variables, they were still a bit perplexed, mainly around “height depends on your weight….  weight depends on your height… both sound the same to me?”. Since this [...]

Most students will be finishing up with the core section soon, and moving on to their first module. Congrats – you made it through the largest part of the course! As a chapter summary, and a way of revising everything you’ve just learned, I suggest having a crack at the core section from one of [...]