In this situation Sherrie is forecasting her sales for this upcoming weekend. There are different types of forecasting methods however Sherrie is specifically using a lost-horse forecasting. Lost-horse forecasting is defined as taking the last known value of an item, listing the factors that could impact, assessing whether they'd have a negative or positive affect on the situation and then finalizing the forecast. Since, Sherrie believes that the rain will have a negative affect this time on her sales from $800 and bringing them down to $600, she is using a lost-horse forecast to base her outcome.