Nana:
I'll answer the easy one. You must have had a bad morning. Assume a stock trades as follows:
All are Open, High, Low, Close. Stock trades are reported by minute, not by tick.
1, 3, 5, 5
5, 5 ,5, 5
4, 4, 2, 2
2, 2, 2, 2
3, 3, 1, 3
A 5 minute report would be:
1, 5, 1, 3...