Answer:
0.207 = 20.7% probability that exactly 10 of these are from the second section
Step-by-step explanation:
The students are chosen without replacement, which means that the hypergeometric distribution is used.
Hypergeometric distribution:
The probability of x sucesses is given by the following formula:
In which:
x is the number of sucesses.
N is the size of the population.
n is the size of the sample.
k is the total number of desired outcomes.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.
In this question:
20 + 30 = 50 total students, which means that
30 students from the second section, which means that
First 15 graded projects, so sample of 15, which means that
a. What is the probability that exactly 10 of these are from the second section
This is P(X = 10).
0.207 = 20.7% probability that exactly 10 of these are from the second section