In: Statistics and Probability
The IRS reports that 15% of returns where the adjusted gross income is more than $1,000,000 will be subject to a computer audit. For the year 2017, Fred Friendly, CPA, completed 16 returns where the adjusted gross income was more than $1,000,000.
a. What is the probability exactly one of these returns will be audited?
b. What is the probability at least one will be audited?
The available information shown in below table,
| Sample Size | Percentage | 
| n = 16 | p = 15% = 0.15 | 
a)
Calculate the probability that exactly one of these returns will be audited.

= 16 × 0.15 × 0.0874
= 0.2097
Hence, the required probability is, 0.2097.
b)
Calculate the probability that at least one will be audited.
P(X ≥ 1) = 1 – P(X < 1)
= 1 – P(X = 0)
= 1 – (1 × 1 × 0.0743)
= 1 – 0.0743
= 0.9257
Hence, the required probability is, 0.9257.