Women$$s track and field times for the 50$50$m,100$,100$m,200$,200$m,$,$ and 400$400$m races are 5.97$5\mathrm{.}97$s,10.52$,10\mathrm{.}52$s,21.34$,21\mathrm{.}34$s and 47.8$47\mathrm{.}8$s respectively. Which race was run at the fastest average speed?