Step $2$

To calculate the average speed for the time period $1,2,$ we substitute $h=1$ into $v_{\text{a}\text{v}\text{g}}=1\mathrm{.}28-1\mathrm{.}86h,$ and evaluate.

$v_{\text{a}\text{v}\text{g}}=1\mathrm{.}28-1\mathrm{.}86(1)$

$=1\mathrm{.}28-1\mathrm{.}86$

$=$

Similarly, for the time period $[1,1\mathrm{.}5],$ we have the following.

Step $3$

Using the same method, for the time period $[1,1\mathrm{.}1],$ we have the following.

$v_{\text{a}\text{v}\text{g}}=1\mathrm{.}28-1\mathrm{.}86()$

$=,\frac{m}{s}(roundedto$ two decimal places$)$