Education Technology

VIC: Journey to the Stratosphere



Calculate Sx and Sy for a data set with strong correlation and use these values to determine the regression equation y = a + bx. Students use their equation to make prediction (extrapolate) and test the accuracy of these predictions and the limitations of their equation.


  • Linear and statistical calculations: Sx, Sy, R, y = a + bx
  • Correlation
  • Extrapolate
  • Regression

About the Lesson

Maxime Dehaye a French Web Developer and avid photographer released a weather balloon with a range of sensors and video cameras attached. The video can be seen on YouTube, including the on-board telemetry. The data is transcribed and plotted on the calculator whilst the balloon travels skyward towards the stratosphere. Students calculate Sx and Sy using the corresponding formulas and use these results to arrive at the equation y = a + bx. Based on data for the first minute, students make predictions for the altitude of the balloon at 30 minutes generally with surprising accuracy.