To know if there is a relationship between the # of times the advertisement was aired and digital camers sales, you have to plot the 5 pairings on a graph for example with digital camers sales on the y axis and the number of times the advertisement was aired on the x axis.

You can see the graph on the excel file attached :

You can notice that the pairings draw almost a straight line (shown also on the graph). We can say that there's a linear and positive relationship between the 2 different parameters. Positive because when you increase advertisement, you increase sales.

Thank you in advance for giving me a nice feedback.