Consider PepsiCoâs quarterly net revenue as shown in Table 14.4.5.
a. Draw a time-series plot for this data set. Describe any trend and seasonal behavior that you see.
b. Plot the moving average values on the same graph as the original data. Comment on what you see. c. Find the seasonal index for each quarter. Which is generally the best quarter for PepsiCo? About how much larger are net sales in this quarter, as compared to a typical quarter?
d. Plot the seasonally adjusted series with the original data.
e. Find the regression equation to predict the long-term trend in seasonally adjusted sales for each time period, using 1, 2,⦠for the X variable.
f. Does PepsiCo show a significant trend (either up or down) over this time period as indicated by the regression analysis in the previous part of this problem?
g. If we omit the first year (the four observations in 2010) but still use the other seasonally adjusted values as we did in the previous regression, does PepsiCo show a significant trend (either up or down) over this time period?
Table 14.4.5:
TABLE 14.4.5 Quarterly Net Sales for PepsiCo Year Net Revenue ($ Billions) 2010 9.368 2010 14.801 2010 15.514 2010 18.155 2011 11.937 2011 16.827 2011 17.582 2011 20.158 2012 12.428 2012 16.458 2012 16.652 2012 19.954 2013 12.581 2013 16.807 2013 16.909 2013 20.118 2014 12.623 2014 16.894 2014 17.218 2014 19.948 Source: 10-K Annual Reports, accessed at http://www.sec.gov/ edgar.shtml on October 1, 2015.
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