Question

1. Suppose that about 85% of graduating students attend their graduation. A group of 22 graduating students is randomly chosen.
   

1. In words, define the random variable X.
2. List the values that X may take on.
3. Give the distribution of X. X ~ _____(_____,_____)
4. How many are expected to attend their graduation?
5. Find the probability that 17 or 18 attend (Practice with calculator).
6. Find the probability that at most 15 will attend (practice with calculator).
7. Based on numerical values, would you be surprised if all 22 attended graduation? Justify your answer numerically.

Answer 1

1. In words, define the random variable X.

Ans X=attend of graduation studentsThe

2 values that X may take on
Ans: X takes value

X=0,1,2,---------------------------,22

3.Give the distribution of X.

Ans: X ~ Binomial (n=22,p=0.85)

4:How many are expected to attend their graduation?

Ans: E(X)=n*p

E(X)=22"0.85=18.7

5)Find the probability that 17 or 18 attend

Ans:

Probability=P(X=17)+p(X=18)

=0.1262+0.1987=0.3249

probability that 17 or 18 attend is 0.3249

Find the probability that at most 15 will attend

Ans: =0.0368