From the real life situation described in the prior DQ 1, I found out the form of the equation that can be used to analyze situations wherein decisions have to be made. This linear equation is that of the slope: y = ax + b, wherein x is the independent value and its value is fixed. In the problem 40, the x denotes the fixed rate for each minute used. The variable a is the number of minutes consumed for the call and b is the fixed amount the company charged just for using the service.
The variable y is the dependent variable and the total amount for the whole service, depending on the number of minutes used. Figure 1, based on problem 40 (McGraw-Hill Companies, 2005) will help to further illustrate the use of the equation. Based on the graph, Company A costs more than Company B up until a certain point, which is when the sum of the calls Rafaella made in one month was 45 minutes. On the other hand, when she made 60 minutes worth of calls in one month, it is seen that Company B started to become a bit more expensive than Company A.
Thus, based on the results, Rafaella should choose based on her own estimate of her usage of long-distance calls. If she’ll rarely make calls or call for only a few minutes each month, she should stay subscribed at Company B. However, if she thinks that her total calls would exceed 60 minutes per month, then it is advisable for her to subscribe to Company A. Table 1. Total charges for total minutes of of long-distance calls in one month for Company