This is a very simple exercise whose purpose is to get you acquitted with the use of the SPIM simulator. For a good view of SPIM commands and assembler directives, see the SPIM Overview presentation
The example program for this Lab manipulates an array and calculate the mean of the values present on the array. For practice with the SPIM, try to discover the global symbols defined on the example program and the value of their data.
Once you discover the name of the global symbols in the example program, try to insert some breakpoints on the program and make a step by step execution. Try to figure out how much pseudo-instructions the example program have.