A student has enrolled for the first time at a University. The probability of receiving it is 85% if you obtain a scholarship and 45% if you do not obtain one. If the probability of obtaining a scholarship is 30%. i) Determine the probability that the student receives a scholarship. ii) If the student receives a scholarship, determine the probability that he or she received a scholarship.
Accepted Solution
A:
To solve this problem, we can use conditional probability. Let's break it down step by step:
i) Determine the probability that the student receives a scholarship.
The probability of receiving a scholarship is given as 30%. Therefore, P(Scholarship) = 0.30 or 30%.
ii) If the student receives a scholarship, determine the probability that he or she received a scholarship.
This is a conditional probability problem, and we want to find the probability that the student received a scholarship given that they received it. We can denote this as P(Scholarship | Received Scholarship).
We can use Bayes' theorem to calculate this:
P(Scholarship | Received Scholarship) = [P(Received Scholarship | Scholarship) * P(Scholarship)] / P(Received Scholarship)
We already know:
- P(Scholarship) = 0.30 (from part i)
- P(Received Scholarship | Scholarship) = 0.85 (probability of receiving if you obtain a scholarship)
Now, we need to find P(Received Scholarship), which can be calculated using the law of total probability. We can calculate it as follows:
P(Received Scholarship) = P(Received Scholarship | Scholarship) * P(Scholarship) + P(Received Scholarship | No Scholarship) * P(No Scholarship)
- P(Received Scholarship | No Scholarship) = 0.45 (probability of receiving if you do not obtain a scholarship)
- P(No Scholarship) = 1 - P(Scholarship) = 1 - 0.30 = 0.70 (probability of not obtaining a scholarship)
Now we can calculate P(Received Scholarship):
P(Received Scholarship) = (0.85 * 0.30) + (0.45 * 0.70)
P(Received Scholarship) = 0.255 + 0.315
P(Received Scholarship) = 0.57
Now, we can calculate P(Scholarship | Received Scholarship) using Bayes' theorem:
P(Scholarship | Received Scholarship) = (0.85 * 0.30) / 0.57
P(Scholarship | Received Scholarship) = 0.255 / 0.57
P(Scholarship | Received Scholarship) β 0.4474
So, if the student receives a scholarship, the probability that they received a scholarship is approximately 0.4474, or 44.74%.