In: Economics
Answer is “Substitute goods”
With cross price elasticity of 3.5 , meaning demand for large drinks increase with respect to increase in price of medium drinks then they are substitute goods. Substitute goods have positive cross-price elasticities of demand
If good A is a substitute for good B, like coffee and tea, then a higher price for B will mean a greater quantity of A consumed. Complement goods have negative cross-price elasticities