Problem I

The following table contained the information necessary for the determination of the own$-$price elasticity of three goods I, II and III but some of these information are now missing.

$\backslash$table$[[,\%$ change in Price,$\%$ change in Quantity,Own$-$Price Elasticity$],[$Demand for good I,$-20\mathrm{.}85\%,15\mathrm{.}95\%,c$