1. The problem asks for the minimum value of the data represented by a box-and-whisker plot. 2. A box-and-whisker plot shows the minimum, first quartile, median, third quartile, and maximum values of a data set. 3. The minimum value is represented by the leftmost whisker on the plot. 4. According to the description, the whiskers extend approximately from 25 to 90. 5. Therefore, the minimum value of the data is $25$. Final answer: $25$