Dimensional Analysis help now!?

Answering questions like this is alot simpler if you set up conversion factors as you go.

Start with what you know/what you're given, and convert the units one by one until you get the units you want.

So, you're given years as units and want to convert years to seconds.

1.5 years x (365.25 days/1 year) x (24 hours/ 1 day) x (60 min/ 1 hour) x (60 sec/ 1 min) = answer

see that in the first step, the years unit cancels with the years unit in your conversion unit, and so on all the way to seconds until all you're left with is seconds as your units. this is how you know your answer is always right.

Doing the math, you get 47,336,400 seconds in 1.5 years.

Do the same thing to convert yards to cm.

4.5 yards x (3 feet/1 yard) x (30.48 cm / 1 foot) = 411.48 cm in 4.5 yards.

Hope this helped. Good luck.