The data of bus and subway ridership and tourists for the summer months in London, England for the past 16 years has been collected by the city officials (see the table below). Answer the following questions, Q1 & Q2. Note that you must include Excel formulas/calculations showing how you arrive at the answer.

Q1: Bus and subway ridership is believed to be tied considerably to the number of tourists visiting the city. The city official considers the use of associate method (i.e., linear regression model) to forecast ridership based on the number of tourists during summer of the same year. What is expected ridership if 10 million tourists expected to visit London next year (year 17)?

Q2: The city official was told that certain bus and subway lines would need to be re-designed by next spring if the ridership next summer exceeds 3.5 millions. Estimate the probability that such re-designing will be needed.