// Computing a histogram, just the basics, no error checking. // lowest height possible in tenths of an inch static final int LOWEST = 5 * 12 * 10; // how wide a range each bin covers in tenths of an inch static final int BIN_WIDTH = 1 * 10; // how many bins we will collect static final int BIN_CAPACITY = 18; ... // allocate and zero array to store the counts for each bin int[] bin = new bin[ BIN_CAPACITY ]; for (student : students) { // height is a given student's height in tenths of a inch int height = student.getHeightInDeciInches(); // figure out which slot this student fits in. binNumber = (height - LOWEST) / BIN_WIDTH; // increment the appropriate bin for that student's height bin[binNumber]++; } // Now feed your bin totals into a bar charting package such as Excel, // or print them out crudely using *s to represent the bars.