A researcher wants to study the effect of a price change on the sales of various brands of a certain product. Assume the market is made up of four brands - W, X, Y and Z - and the price change (decrease) for brand W is introduced immediately after time to. Assume every respondent buys exactly one unit of the product in each period. Data on number of respondents buying each brand in each period, based on a panel, are as follows: to WAYN X W 175 0 25 50 t X 25 100 0 0 Y 0 25 50 0 70202 Z 25 25 Note: Confine your attention only to the data presented. Assume the world starts at to and stops after t and the strategies of brands X, Y, and Z are unchanged between to and ti. a) On the basis of these data, is the price change for brand W successful? Focus on market share as the relevant criterion. Show your calculations. (8 points) (Note: Market share is the percent of total sales in an industry that generated by a particular company)