Question 8 The length of a product's life cycle: O may be as long as 100 years. O varies widely across products. O depends on the ease of entry to the market for competitors. O may be as short as 90 days. O all of the above. Question 9 Regarding product life cycles, a good marketing manager knows that: O once a market goes into sales decline, oligopoly conditions set in. O a company's marketing mix usually should be kept constant over the product life cycle. O industry profits are increasing well after sales start to decline. O entirely different target markets may be involved at different stages of the product life cycle. O all of the above. 1 pts 1 pts