Need answer on question number 4. a) b) c).

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The sales, S, of a product have declined in recent years. 2.0 million were sold in 2009 but only 1.8 million sold in 2013. Assume the sales are decreasing according to the exponential decay model, S (r) = Sue"I . a) Find the value I: and write an exponential function that describes the number sold after time, t, in years since 2009. Round k to 3 decimal places! 13) Estimate the sales of the product in the year 2015. Round to the nearest whole unit. 0) In What year will only 0.6 million units of the product be sold