Data Management Help
Hey guys!
Alright, so im having trouble with my data management homework. About 2/8 questions i get wrong, the answer was provided but not the progress. I`ve attempted these questions, but i always seem to get off. Basil seems like a smart community and i hope this works ;3
1.The weather pattern for a certain region is as follows. On a sunny day, there is a 50% probability that the next day will be sunny, a 30% chance that the next day will be cloudy, and a 20% chance that the next day will be rainy. On a cloudy day, the probability that the next day will be cloudy is 35%, while 40%l likely to be rainy and 25% likely to be sunny the next day. On a rainy day, there is a 45% chance that it will be rainy the next day, a 20% chance that the next day will be sunny and a 35% chance that the next day will be cloudy. If it is cloudy on Wednesday what is the probability it will be sunny on friday? [0.2925]
2.The weather near a certain seaport follows this pattern. If it is a calm day, there is a 70% chance that the next day will be calm, otherwise it will be stormy.If it is a story day, there is a 50/50 chance that the next day will also be stormy. If it is stormy two days in a row what are the chances that at least one of the next 3 days will be story? [0.755]
I tried the compliment process, but didnt get it right. I think my calculation or brain process is wrong. Any help? Please also state what you did. This would be greatly appreciated! Thank you Basil!
5 Comments • Newest first
ah , i seriously can't thank you guys enough...this helps SO MUCH ;3
now i understand it ;3
thank you!thank you!thank you!thank you!thank you!thank you!thank you!thank you!thank you!thank you!thank you!
Lol saying Basil seems like a smart community
[quote=ItzPootz]Yeah, not my best work, but I'm tired; forgive me I hope that the general idea is communicated though.[/quote]
It's fine, you did a well job, just hard to interpret.
[quote=ItzPootz]1. Total Probability of being Sunny on Friday = (Probability Sunny after Cloudy)*(Prob. Sunny after Sunny) + (Prob. Cloudy after Cloudy)*(Prob.Sun. after C) + (Prob. Rain after C)*(Prob. Sun. after R.)
You see that it's the addition of the chance of rain/sun/cloud after a cloudy day(wednesday) times the chance of a sunny day after those. (.25*.5+.35*.25+.4*.2) = ?
2. It's easier to find the chance that it ISN'T stormy for three days in a row after a stormy day. You'd do this similar to the last problem (Prob.Calm.after S.)*(Prob.Calm after C)*(Prob.Calm after C) = 0.245 = (Prob. Calm for 3 days straight after a Storm)
(Prob. of at least one storm in 3 days) = 1 - (Prob. Calm for no storms in 3 days) = 1 - 0.245 = ?[/quote]
This is messy math and you may confuse people if you don't stick to parallelism. If you're going to write out the words, it's best to stick to writing out the words for all the sections otherwise people may think a letter represents some variable and not an acronym. Come to think of it, I don't even think 1 letter can act as an acronym X_X.
Formula looks good but it needs to be more clear and organized if anyone is going to get it.
just sayin
I'm too lazy to do this but everything becomes more apparent when you write it all out.
Here's the simple format.
[weather of day = probability of next day (adds up to 100%)] <--Key
Sunny Day = 50% sunny, 30% cloudy, 20% rainy
Cloudy Day= 25% sunny, 35% cloudy, 40% rainy
Rainy Day= 20% sunny, 35% cloudy, 45% rainy
I arranged them in order for a better visual. You can figure out the answer from here on. If the answer is 2 days apart then you can use the 1st day to figure out the 2nd day and the 2nd day to figure out the 3rd (this is where probability and math comes in from what you've learned).
It's going to involve fractions.