3. Consider an advanced statistics class which consists of 20 Statistics majors, 15 Mathematics majors, 10 Computer Science majors, and 5 Electric Engineering majors. Suppose a random sample of size 10 is drawn from this course without replacement. What is the probability that the sample contains 5 Statistics majors, 3 Mathematics majors, 2 Computer Science majors, and 0 Electric Engineering majors?

Respuesta :

Answer: 0.0309

Step-by-step explanation:

Given: In advanced statistics class, there are 20 Statistics majors, 15 Mathematics majors, 10 Computer Science majors, and 5 Electric Engineering majors.

Total = 20+15+10+5 =50

Number of combinations of selecting r things out of n = [tex]^nC_r=\dfrac{n!}{r!(n-r)!}[/tex]

The number of ways to choose a sample of 10 put of 50=[tex]^{50}C_{10}=\dfrac{50!}{10!40!}[/tex]

Number of ways to choose  5 Statistics majors, 3 Mathematics majors, 2 Computer Science majors, and 0 Electric Engineering majors = [tex]^{20}C_5\times ^{15}C_3\times ^{10}C_2\times ^5C_0\\\\=\dfrac{20!}{5!15!}\times\dfrac{15!}{3!12!}\times\dfrac{10!}{2!8!}\times\dfrac{5!}{5!0!}[/tex]

Required probability = [tex]\dfrac{\frac{20!}{5!15!}\times\frac{15!}{3!12!}\times\frac{10!}{2!8!}\times\frac{5!}{5!0!}}{\frac{50!}{10!40!}}= 0.0309[/tex]

Hence, the required probability = 0.0309