The consumer price index (CPI) is calculated by averaging the prices of various items after assigning a weight to each item. The following table gives the consumer price indexes for selected years from 1940 through 2008, reflecting buying patterns of all urban consumers, with x representing years past 1900. Find an equation that models these data. (Round your coefficients to three decimal places.) Use the model to predict the consumer price index in 2013. (Round your answer to one decimal place.) According to the model, during what year will the consumer price index pass 300? The following table gives the average number of students per computer in public schools for selected school years that ended in 1985 through 2006. (a) Find an exponential model for these data. Let x be the number of years past 1980. (Round your coefficients to five decimal places.) ? = (b) Is this model an exponential growth function or an exponential decay function? exponential growth exponential decay (c) How many students per computer in public schools does this model predict for 2017? (Round your answer to two decimal places.) students per computer