In 1987 and 1988 news stand sales for North American magazines were declining by an annual rate of 10 percent, regardless of the magazine category.In order to stop this decline, TV Guide magazine conducted a consumer contest to entice readers to try the product and encourage infrequent readers to become frequent readers.Data was collected for 50 weeks, 20 weeks prior to the contest, the 10 weeks of the contest, and 20 weeks after the contest.The following is a time series plot of this data.What does this plot tell you about the effectiveness of the contest? See image:Choose what you believe is the best answer from the following answers:i) There is a downward trend beginning around time period 25. This is a special cause.ii) The plot suggests that the sales declined in the 20 weeks after the contest, thus it looks like the contest was not effective.iii) The contest was very effective during the 10 weeks in which it was operating; however this effectiveness did not last very long.iv) Both i) and ii) are correct.

Time Series Plot of Sales 450000 425000 400000 Sales 375000 350000 10 15 20 25 30 35 40 45 50 Index