Please help me verify these. If they are off please let me know! Thanks!

QUESTION 2 2. The relevant range are fixed costs for a range of volume but increase to a higher level when the upper bound of the range is exceeded. True False QUESTION 3 Account analysis is the most common approach to estimating fixed and variable costs. True False QUESTION 4 The break-even-point is not the number of units that must be sold for a company to break even. True False QUESTION5 5. The contribution margin is the difference between the expected level of sales and the variable costs of the level of sales. True O False QUESTION 6 6. In CVP the primary assumption is that costs can be separated into their mixed and variable components. O True False