Ans: (a) $a=11.3$, $b=15.3$ (b) Yes
-
$\begin{array}{rcl}
18.1 – a & = & 6.8 \\
a & = & 11.3
\end{array}$$\begin{array}{rcl}
b – 12.1 & = & 3.2 \\
b & = & 15.3
\end{array}$ - Note that the longest time taken by the students to finish a $100\mbox{ m}$ race after the training is $18.1-2.9 = 15.2\mbox{ s}$, which is shorter than the upper quartile (i.e. $15.3\mbox{ s}$) of the data before training. Therefore I agree the claim.
