Question 1148592
<pre>
x minutes    y cost
    36         17.53
    59          ?
    75         21.82
</pre>
price {{{(21.82-17.53)/(75-36)=0.11}}}


point-slope form, {{{y-17.53=0.11(x-36)}}}


{{{highlight(y=0.11(x-36)+17.53)}}}
substitute x with 59 to find the asked cost.