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Cost varies directly as time and the cost is $8 when the time is 2 hours, what is the constant of proportionality?

Answer 1

Eli Assouline

#k=4#

#"let C be cost and t be time then"#

#"the initial statement is "Cpropt#

#"to convert to an equation multiply by k the constant"# #"of variation"#

#rArrC=kt#

#"to find k use the given condition"#

#"cost "=8" when "t=2#

#C=ktrArrk=C/t=8/2=4#

#rArr"constant of proportionality "=4#

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Answer 2

Eva Abramson

The constant of proportionality can be found by dividing the cost by the time. In this case, since the cost is $8 when the time is 2 hours, the constant of proportionality is$ 8 divided by 2 hours, which equals $4 per hour. Therefore, the constant of proportionality is$ 4 per hour.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.