FALL SEMESTER 2020
MTH 2210-C: INTRODUTION TO APPLIED STATISTICS
INSTRUCTOR: DR. GABRIEL OKELLO
DATE: NOVEMBER 19, 2020
INDIVIDUAL EXERCISE TWELVE
INSTRUCTIONS
 Attempt All Questions
1. The probability distribution for a random variable 𝑋 follows:
𝑃(𝑥)
0.20
0.15
0.25
0.40
𝑥
20
25
30
35
a. Is this probability distribution valid? Explain
b. What is the probability that 𝑋 is greater than 25?
c. Find the expected value and standard deviation of 𝑋.
2. A random variable 𝑋 has the following probability distribution
𝑥
𝑝(𝑥)
0
1
𝑎
2
3𝑎
3
5𝑎
4
7𝑎
9𝑎
a. Determine the value of 𝑎
b. Find 𝑃(𝑋 < 4), 𝑃(𝑋 ≥ 2), 𝑃(1 < 𝑋 < 6)
5
11𝑎
6
13𝑎
7
15𝑎
8
17𝑎