Thanks for looking at it nirgrahamuk and FJCC.
Yesterday's 7.3 prediction is now 7.48 today. It is 7,483,107 cents.
Apologies. I tried simplyfy problem but that may have caused more harm.

In above summary table,
Sum_X = Predicted value for rest of March. Actual prediction for 2020 March is 4,708,408
Sum_RestNB = Observded values from 14th - 31st of Mar.
Sum_ToDateNB= Observed values from 1st - 14th Mar.
accuracy = My simple calc to see how good the prediction is.
API = Sum_ToDateNB + Sum_X = 2,774,699 + 4,708,408 = 7,483,107