Discrete Random Variables Can only assume a countable number of values Examples: ■Roll a die twice Let X be the number of times 4 comes up (then X could be 0,1,or 2 times) Toss a coin 5 times. Let X be the number of heads (then X=0,1,2,3,4,or5) Chap 5-5 Tongji University School of Economics Management Statistics for Managers Using Microsoft ExcelStatistics for Managers Using Microsoft Excel Chap 5-5 Tongji University School of Economics & Management Discrete Random Variables ▪ Can only assume a countable number of values Examples: ▪ Roll a die twice Let X be the number of times 4 comes up (then X could be 0, 1, or 2 times) ▪ Toss a coin 5 times. Let X be the number of heads (then X = 0, 1, 2, 3, 4, or 5)