There is an inverse relationship between the price of a bond and the bond's required return.
Duration is an estimate of the percentage change in the bond's price in response to a 100 basis point change in required return.

The presence of substitutes for a good raises the elasticity of the good. This is because under a price increase for tomatoes, consumers will switch to other vegetables that are now relatively lower priced. There are few good substitutes for salt and therefore the price elasticity of salt is much lower than that for tomatoes.

Implicit costs are those costs associated with the use of resources owned by the firm. For these, there are no explicit monetary payments and thus represent implicit costs. Examples of such costs include the use of a spare warehouse or the services provided by a proprietor for his own business.

(1173.80 - 861.62)/(2 x 1000 x 0.01) = 15.61

LIFO reports proper income or profit when prices are rising. FIFO would overestimate it.