What you’ll learn to do: Use a linear regression t-test with p-values and critical values

It appears from a scatterplot that there is a positive linear relationship between temperature and ice cream sales. Should we use the least-squares regression line to make a prediction about ice cream sales from temperature? How strong does the correlation coefficient need to be to say that the correlation is statistically significant? We will be addressing these questions by using a test of significance for the population correlation coefficient.