Paul and Michael sell magazine subscriptions by telephone. Paul is paid $1.00 for every five calls he makes, while Michael is paid $1.00 for every subscription he sells, regardless of the number of calls he makes. Paul’s telephoning is reinforced on a schedule, whereas Michael’s is reinforced on a schedule. Group of answer choices Variable-ratio; fixed-ratio Fixed-ratio; variable-ratio Fixed-ratio; variable-interval Fixed-interval; variable-ratio

The business cycle is the periodic but irregular up-and-down movement in economic activity, measured by fluctuations in real gross domestic product (gdp) and other macroeconomic variables. a business cycle is typically characterized by four phases—recession, recovery, growth, and decline—that repeat themselves over time. economists note, however, that complete business cycles vary in length. the duration of business cycles can be anywhere from about two to twelve years, with most cycles averaging six years in length. some business analysts use the business cycle model and terminology to study and explain fluctuations in business inventory and other individual elements of corporate operations. but the term "business cycle" is still primarily associated with larger (industry-wide, regional, national, or even international) business trends.