What is probability?

Probability is the basic need of communication in Engineering, we discuss all possibilities

That can take place.   Basically, it tells about chances of any outcome can take place.

All software, we make use all possibilities and their chances of favour and against.

In the cases where sample space is very small, we normally use favourable outcomes over total outcomes but when sample space is very large, we can’t make it manually, we are dependent on binomial, poisson and normal distribution. When p(SUCCESS) is intermediate in size and n(no. Of outcomes) is large, we use binomial distribution and when p is very small and n is very large, we use poisson distribution.

Probability is a way that many people understand basically. Since words like “proportion”, “likelihood”, “chance” and “possibility” are used in everyday speech. Following are the examples of fact statements of probability which might be heard in any of the business situation: -

1)There is a 30% chance of this job not to be finished in time.

2)There is every likelihood that the business will be making a great profit the following year.

The concept of probability is really very important. It has discovered a very extensive application in the development of every physical science. Sometimes a person explains without actually discussing probability. The probability is a way which mainly measures the degree of uncertainty and therefore of certainty of the occurring of events.

There are some situation for all of you doing communication subjects in branches ECE, CSE,IT

They all must practice of following questions

                                                                                                                       

Daily life situation

1. Suppose that the reliability of a HIV test in specified as follows:

Of people having HIV, 90% of the test detect the disease but 10% go undetected. Of people free of HIV, 90% of the test are judged HIV –ve but 1% are diagnosed as showing HIV +ve. From a large population of which only 0.1% have HIV, one person is selected at random, given the HIV test, and the pathologist reports him/her as HIV +ve. What is the probability that the person actually has HIV ?

2. A doctor from panipat is to visit a patient. From the past experience, it is known that the probability that he will come by train, bus, scooter or by other means of transport, are respectively   The probabilities that he will be late are  , if he comes by train, bus and scooter respectively, but if he comes by other means of transport, then he will not be late. When he arrives, he is late. What is the probability that he comes train?

3. Shakuni mama is known to speak truth 3 out of 4 times. He throws a die and reports that it is a six. Find the probability that it is actually a six.

4. Lal path lab panipat blood test is 99% effective in detecting a certain disease when it is in fact, present. However, the test also yields a false positive result for 0.5% of the healthy person tested (i.e., if a healthy person is tested, then with probability 0.005, the test will imply he has the disease). If 0.1 per cent of the population actually has the disease, what is the probability that a person has the disease given that his test is positive?

5. Assume that the chances of a patient having a corona is 40%. It is also assumed that a meditation and yoga course reduce the risk of heart attack by 30% and prescription of certain drug reduces its chances by 25%. At a time, a patient can choose any one of the two option with equal probabilities. It is given that after going through one of the two options the patient selected at random suffers a corona. Find the probability that the patient followed a course of meditation and yoga?

6. In answering a question on a MCQ test with 4 choices per question, a student of GEETA ENGG COLLEGE PANIPAT knows the answer, guesses or copies the answer. Let  be the probability that he knows the answer,   be the probability that he quesses and   that he copies it. Assuming that a student, who copies the answer, will be correct with the probability  , what is the probability that the student knows the answer, given that he answered it correctly?

IN ALL ABOVE CASES WE ARE ONLY DEPENDENT ON PROBABILITY

Author

Mohinder Malhotra

GGI PNP