The monthly cost (in dollars) of a long-distance phone plan is a linear function of the total calling time (in minutes). The monthly cost for 50 minutes of calls is $17.63 and the monthly cost for 77 minutes is $20.87 . What is the monthly cost for 58 minutes of calls?

Question

The monthly cost (in dollars) of a long-distance phone plan is a linear function of the total calling time (in minutes). The monthly cost for 50 minutes of calls is $17.63 and the monthly cost for 77 minutes is $20.87  . What is the monthly cost for  58 minutes of calls?

anonymous · Answer

50 minutes  ------> $17.63   
58 minutes--------> $ X

use cross multiply..

50*$x=58*$17.63

$x=(58*$17.63)/50

... continoue

anonymous · Answer

x=20.4508    so for  58 minutes of call will cost $20.4508

anonymous · Answer

its wrong, look at this solution http://www.algebra.com/algebra/homework/Graphs/Graphs.faq.question.174364.html