 # 8.03 Fitting a straight line - least squares regression

## Interactive practice questions

The average monthly temperature and the average wind speed in a particular location was plotted over several months. The graph shows the points for each month’s data and their line of  best fit.

Use the line of best fit to approximate the wind speed on a day when the temperature is $5$5°C.

Easy
Less than a minute

A plane's altitude ($A$A) is measured at several times ($t$t) during its descent.

The data and the line of best fit are shown below.

Chirping crickets can be an excellent indication on how hot or cool it is outside. Different species of crickets have different chirping rates but for a particular species the following data was recorded.

The equation $d=58-0.63h$d=580.63h represents the line of best fit relating the air humidity, $h$h, and the depth in metres, $d$d, of snow in an area.

### Outcomes

#### 9.D1.3

Create a scatter plot to represent the relationship between two variables, determine the correlation between these variables by testing different regression models using technology, and use a model to make predictions when appropriate.

#### 9.D2.1

Describe the value of mathematical modelling and how it is used in real life to inform decisions.