To create a box plot for the data {27, 31, 30, 33, 29, 25, 28}, arrange the data in ascending order, find the minimum, maximum, median, first quartile (Q1), and third quartile (Q3), then draw a number line and plot the minimum, Q1, median, Q3 and maximum of the data to create the box plot. The resulting box plot shows the center, spread and outliers of the data.