inquiry about chapter 26 of ‘Forecasting’

I have some inquires regarding ‘ Forecasting’of chapter 26.
1) on page 92, ‘the trend adjusted for seasonal variations’ says: ‘ we could say that the trend has moved from 2702 to 2451 in 7 jumps , this is (2702-2451)/7=36/season.
I want to say that figure 2702 can not be found from the above diagram, just 2720 can be found. Meanwhiel, (2720-2451)/7=38/season, not 36.

2) on page 93, ‘Exponential smoothing’, the prediction for Q3/Yr3
75%*2832+25%*2451=2736, the calculation based on last time’s actual resluts and last time’s predicted results.

But for the prediction for Q4/Yr 3,
75%*1920+25%*2737=2,124
according to the explanation of ‘exponential smoothing’, the predicted results should be based on the last last time’s actual resluts and last time’s predicted results.

I guess the prediction for Q4/Yr 3, should be:
75%*2160+25%*2737=2304.

Could anyone can help to have a look at these inquiries?