$\backslash$table$[[$Tablet$,$Cost $($$$),\backslash$table$[[$Operating$],[$System$]],\backslash$table$[[$Display$],[$Size$],[($inches$)]],\backslash$table$[[$Battery$],[$Life$],[($hours$)]],\backslash$table$[[$CPU$],[$Manufacturer$]]],[$Acer Iconia W$510,599,$Windows,$10\mathrm{.}1,8\mathrm{.}5,$Intel$],[$Amazon Kindle Fire HD$,299,$Android,$8\mathrm{.}9,9,$TI OMAP$],[$Apple IPad $4,499,$iOS,$9\mathrm{.}7,11,$Apple$],[$HP Envy X$2,860,$Windows,$11\mathrm{.}6,8,$Intel$],[$Lenovo ThinkPad Tablet,$668,$Windows,$10\mathrm{.}1,10\mathrm{.}5,$Intel$],[$Microsoft Surface Pro,$899,$Windows,$10\mathrm{.}6,4,$Intel$],[$Motorola Droid XYboard,$530,$Android,$10\mathrm{.}1,9,$TI OMAP$],[$Samsung Ativ Smart PC$,590,-$Windows,$11\mathrm{.}6,7,$Intel$],[$Samsung Galaxy Tab,$525,$Android,$10\mathrm{.}1,10,$Nvidia$],[$Sony Tablet S$,360,$Android,$9\mathrm{.}4,8,$Nvidia$],[$a$.$ What is the averane cost for,,,,,$]]$

b$.$ Compare the average cost of tablets with a Windows operating system to the average cost of tablets with an Android operating Average cost with a Windows operating system $=$$

Average cost with an Android operating system $=$$