Juan Valdez Trades in His Old Donkeys for Two New

Essay

Juan Valdez trades in his old donkeys for two new llamas in order to transport his mountain grown coffee to the marketplace.Llamas make excellent pack animals and are surefooted,so I should be able to spend more time harvesting and less time wrangling animals,Juan thought to himself as he led the two back to his mountain farm.Much to his dismay,the first time he tried to strap the bags of coffee beans to his new llamas they resisted by running away and when he got close,they spit copiously.However,he was persistent and methodical,and he noticed that things went a little better each day.The time it took to get the llamas loaded up is summarized in the table.
$$\begin{array} { | l | l | l | l | } \hline \text { Day } & \text { Time } ( \mathrm { min } ) & \text { Day } & \text { Time (min) } \\\hline 1 & 140 & 5 & 84 \\\hline 2 & 116 & 6 & 79 \\\hline 3 & 100 & 7 & 79 \\\hline 4 & 93 & 8 & 76 \\\hline\end{array}$$
What learning rate is evident from the data?
How long will it take to load up the llamas next month (on the 30th attempt)if the same learning pattern continues?