Answer: 129
Step-by-step explanation:
the mean is the average of the data. including x, there are 6 data points
average = total/6
average = (98 + 123 + 105 +114 +109 + x) / 6
113 = (98 + 123 + 105 +114 +109 + x) / 6
113 = (549+ x) / 6
678 = 549 + x
x = 129