All of the following are assumptions of cost-volume-profit analysis except a. the sales mix is constant. b. costs can be divided into fixed and variable components. c. there is no change in inventory quantities during the period. d. within the relevant range of operating activity, the efficiency of operations can change.

d. within the relevant range of operating activity, the efficiency of operations can change.

Explanation:

Cost-volume-profit analysis is also known as the break even analysis, it is an important tool in predicting the volume of activity, the costs to be incurred, the sales to be made, and the profit to be earned is. It is used to determine how changes in differing levels of activities such as costs and volume affect a company's operating income and net income.

Generally, to use the cost-volume-profit analysis, financial experts usually make some assumptions and these are;

1. Sales price per unit product is kept constant.

2. Variable costs per unit product are kept constant and the total fixed costs of production are kept constant i.e costs can be divided into fixed and variable components.

3. All the units produced are sold i.e there is no change in inventory quantities during the period.

5. The costs accrued are as a result of change in business activities.

6. A company selling more than a product should simply sell in the same mix i.e the sales mix is constant.

Hence, the aforementioned are assumptions of cost-volume-profit analysis except that, within the relevant range of operating activity, the efficiency of operations can change.

the first successful, urban blues recording, selling more than 75,000 copies, was made in year 1920.

mamie smith recorded the first commercially successful example of the urban blues,   with the recording of “crazy blues”."crazy blues" was recorded on august 10, 1920, in new york city. within a month of the release of “crazy blues” it had sold 75,000 copies.