Florence Griffith$-$Joyner $($USA$)$ holds the world record for the women's $200-$meter dash with a time of $21\mathrm{.}34$ seconds, set on September $29,1988,$ in Seoul, South Korea.

a$.$ Calculate a unit rate in terms of meters per second.

b$.$ Determine Florence's speed in terms of miles per hour. $)=1\mathrm{.}61km,1m=3\mathrm{.}28ft,1mi=(5280ft$

c$.$ Calculate a unit rate in terms of minutes per mile. $($Note: $1hr=60$min.$)$

d$.$ What does your answer from c mean in context?