Answer:
Given in the information set as
26, 34, 38, 49, 65, 76, 81
Sum = 369
No of entries = 7
Mean =52.71
When 1213 is included
New sum = 1582
No of entries =8
The new mean will be 197.75
Thus mean will be increased by 145.04
X, y first column ++
Second column +-
Fourth column - -
Fiveth column _+
i'm not sure if you mean 25% <em>off</em> or 25% <em>of</em> so i'll just do both
25% <em>OFF</em>: $150
25% <em>OF</em>: $50
