When a consumer increases units of X-commodity by giving up some units of Y-commodity and even to attain the same level of satisfaction, the marginal rate of substitution will be calculated by
1
Change in X-commodity
Marginal utility of Y-commodity
Marginal utility of Y-commodity
2
Change in Y-commodity
Marginal utility of X-commodity
Marginal utility of X-commodity
3
Change in X-commodity
Change in Y-commodity
Change in Y-commodity
4
Change in Y-commodity
Change in X-commodity
Change in X-commodity