Final answer:
Thirty years ago, most companies relied on periodic inventory systems because technology and information systems were not as advanced as they are today. With periodic inventory systems, companies would physically count their inventory at regular intervals to keep track of stock levels.
Step-by-step explanation:
Thirty years ago, most companies relied on periodic inventory systems. This was because technology and information systems were not as advanced as they are today. With periodic inventory systems, companies would physically count their inventory at regular intervals, such as monthly or annually, to keep track of their stock levels. These systems were often manual and time-consuming, but they were the best option available at the time for companies to monitor their inventory.