# how can probabilities be useful 1

In your own words, answer this unit’s discussion questions in a main post (recommended minimum **200** words), and respond to at least 2 peers’ postings (recommended minimum **75** words).

Think about situations or types of problems where probabilities are useful.

- Describe a specific situation/problem involving probabilities.
- Explain how and why probabilities might be useful in this situation.
- Give a specific example of how probabilities are used in this situation.
- How are probabilities important to decision making in this situation? If they are not, then discuss why not.

Respond:

Good morning everyone,

The sample that I found was in https://examples your dictionary.com/examples of probability.html/

Describe a specific situation/problem involving probabilities

There were four black marbles and there are 5 blue marbles and 1 green marble and 2 black marbles in a bag. p(black) p(blue) p(blue or black) P(not green) p(not purple) sample space there are 12 marbles total (4+5+1+2)=12 probability of ways a certain outcome can occur. Total possible outcome.

p(black) =2/12=1/6= there are 2 black marbles in the bag 12 is your sample space

p(blue)=4/12=1/3 there are 4 blue marble in a bag 12 is your sample space

p(not green)=11/12= there’s 1 green so 12-1=11 that aren’t green 12 is your sample space

p(not purple)=1 12 is your sample space

I will definitely select a marble that is not purple because there are no purple marble in the bag. When ever the chances of something occurring is definitely the probability is 1. I thought that this is a simple one for everyone, but this is just 1 cause I decide that I will do all 4 because I need my grade to better than what it is.

Respond:

I am a mechanic, and one thing that I replace quite often is thermostats. A thermostat is a little device that allows coolant to run through your engine to cool it, and stop the flow when the temp drops below normal operating temperature. It does this with a little piece of metal (I’m not sure if it is steel, aluminum, tin, magnesium, etc) but it reacts to heat. Different thermostats open at different temps, but once the coolant reaches the target temp, it opens and allows coolant to flow, and closes when the temp drops.

Anyway, I have been told that 1 in 5 thermostats have a chance of malfunction straight from he factory; while I have experienced a faulty thermostat I have not been able to find any evidence on this on the web, but we’ll say its true for the sake of this post.

So 1/5 of thermostats are bad, or 20%. ( 5 being the hole number, 20×5=100)

Probabilities are important because you need to know that there is a very real chance of your new part failing and that you will have to restart the procedure of replacing the thermostat again.

A specific example of how of how probabilities are used in this situation is the fact that out of every 5 thermostats manufactured (I am going to say this is true for all manufacturers) 1 will be bad. So if there were 5 people standing in line at the auto parts store and all buying a thermostat for the same vehicle, one of them will get a faulty one. It could be any one of the people, depending on how many were sold at the parts store prior to those 5 people arriving, if the ones sold were part of the same lot.

Probabilities are not so important in this situation, it is a crucial part of the cooling system and therefor there is no choice but to buy one. There are tests you can do to determine its reliability prior to installing it. Other than a run back to the auto parts store, where you can exchange it for a new one, there is no real risk