The average weekly sales for a clothing store between 2004 and 2008 are given below. Average Weekly Sales for a Clothing Store Year Thousand Dollars 2004 38.91 2005 53.47 2006 63.87 2007 72.2 2008 68.1 (a) What behavior suggested by a scatter plot of the data indicates that a quadratic model is appropriate? no concavities a single concavity with no change in direction a single concavity with a change in direction two concavities with no change in direction Correct: Your answer is correct. (b) Align the input so that t = 0 in 2000. Find a function for quadratic model for the data that gives the average weekly sales for the clothing store in thousand dollars, with data from 4 ≤ t ≤ 8. (Round all numerical values to three decimal places.) s(t) = Incorrect: Your answer is incorrect. (c) Numerically estimate the derivative of the model from part (b) in 2007 to the nearest hundred dollars. $ per year (d) Interpret the answer to part (c). In 2007, the average weekly sales for the clothing store were increasing by $ per year.