How do I make a double round to 1 decimal point?

Hi,

How do I make a double round to 1 decimal point?

if (Boost == true)
{
Lots = (LotSize + (LotSize/2));
}


If I use LotSize as 1.5 then Lots would be 2.25 according to the above formula.

I want Lots to round to 1 Decimal Place which is 2.3

How do I do that?

LotSize = NormalizeDouble(LotSize,1);

THANKS!