In the 1990s, e-mail started to be used as a communication tool in businesses. The average daily number of e-mails received by 3 businesses was followed for 5 years with the following results. What do these data indicate about the trend in the use of e-mail?

Year	1	1	1	2	2	2	3	3	3	4	4	4	5	5	5
E-mail per day (average)	1.6	1.5	2.1	4.7	5.5	5.0	8.9	10.1	14.2	30.3	28.5	33.3	59.0	60.7	75.5

1. From the best linear plot, obtain the equation for the most appropriate model. Note also the correlation coefficient. Remember if you plotted log(y), do include the 'log(E)' appropriately in the equation.
2. If the equation includes a log(y), transform it back by reversing the logs. NB: When reversing the logarithm, you must use the base used originally on the data transformation.
3. What is the rate constant per year from this equation? AND calculate the doubling time for this e-mail growth.

Is there any possible problem with this model for the growth of E-mail usage?