The following data represent the number of O-ring failures on the shuttle Columbia for its 17 flights prior to its fatal flight:

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 3 Find the mode number of O-ring failures.

Approach Tally the number of times we observe each data value. The data value with the highest frequency is the mode.