The change in stock market value on Friday would be represented by a negative number, as it is mentioned that the market lost value on that day.
The student's question relates to understanding how changes in stock market values are represented over a period of days. Stock market gains and losses are summarized by the change in value over several days. According to the provided table, the stock market underwent the following changes: Monday saw an increase of +62.53, Tuesday a decrease of -99.16, Wednesday an increase of +3.62, and Thursday a decrease of -21.91. If the market lost value on Friday, the change would be a negative number, representing a decline in value. For example, a Friday loss could be represented by any negative value such as -5.00, -15.34, or any other negative figure indicating a drop in the market's value.