Expenses which have been paid in advance are called​

The usa today reports that the average expenditure on valentine's day is $100.89. do male and female consumers differ in the amounts they spend? the average expenditure in a sample survey of 47 male consumers was $135.67, and the average expenditure in a sample survey of 38 female consumers was $68.64. based on past surveys, the standard deviation for male consumers is assumed to be $34, and the standard deviation for female consumers is assumed to be $17.

How has apple been able to sustain its competitive advantage in the smartphone industry? a. by reducing its network effects b. by targeting its new products and services toward laggards c. by driving the price for the end user to zero d. by regularly introducing incremental improvements in its products

Which external factor has enabled addition of special effects in advertisements and tracking of responses of customers over websites?