Which is LEAST soluble in water at 25 degrees Celsius, lead(II) bromide, chloride, iodide or iodate

Which is LEAST soluble in water 25 degrees Celsius, lead (II) bromide, lead (II) chloride, lead (II) iodide, or lead (II) iodate? How did you obtain this answer?

Least soluble in grams dissolved per litre is lead iodate

see: http://en.wikipedia.org/wiki/Solubility_…
@ 20 C
Lead(II) bromide PbBr2 ======8.6 grams / litre
Lead(II) chloride PbCl2 ======= 1.0 grams / litre
Lead(II) iodate Pb(IO3)2 =========0.024 grams / litre
Lead(II) iodide PbI2 ========0.69 grams / litre


the Ksp's are for 25 Celsius & are found at
http://www.csudh.edu/oliver/chemdata/dat…

they allow us to find molarities soluble
the smallest Ksp for these four, will have the least Molarity
lead(II) bromide PbBr2 === Ksp =4.0 x 10-5
lead(II) chloride PbCl2 ======= Ksp = 1.6 x 10-5
lead(II) iodate Pb(IO3)2 ====== Ksp = 2.6 x 10-13
lead(II) iodide PbI2======= Ksp = 7.1 x 10-9

again, it is Lead (II) iodate
finding it its solubility from its Ksp :
Pb(IO3)2 (s) <=> Pb+2 & 2 IO3-

Ksp = [ Pb+2] [IO3-]^2

2.6 x 10-13 = [X] [2X]^2

4X^3 = 2.6 x 10-13

X^3 = 6.5X 10^-14

X = molarity of Pb(IO3)2 = 4.0 X 10^-5 Molar