Can you help me solve 3 b with details it sgould use Coss Price elasticity formula :

CROSS-PRICE ELASTICITY A final, commonly used elasticity links changes in a good's sales to changes in the prices of related goods. Cross-price elasticity is defined as AQ/Q Ep = APO/ Po where Po denotes the price of a related good or service. If the goods in question are substitutes, the cross-elasticity will be positive. For instance, if a 5 percent cut in a competitor's intercity fare is expected to reduce the airline's ticket sales by 2 percent, we