Answer: -3.5 degrees celcuis.
Step-by-step explanation: I know that each hour the temperature drops 1.8 for four and a half hours. First, I need to find half of 1.8 for the half hour, so 1.8 times 0.5 or 1.8 divided by two equals 0.9. Okay set that aside for a sec. Now i need to find how many degrees dropped in four hours, so i would do 1.8 times four which equals 7.2, now add 0.9 to 7.2 and you get 8.1. Now this is just how much degrees dropped. Now we need to find the temperature. So what you would do, since you know that 8.1 represents how many degrees have dropped since the recent temperature, you would subtract, so 4.6 minus 8.1, you would get -3.5 !