Theoretical DistributionsMCQMTP Dec 2023 Series IQuestion 3523 of 230
All Questions

If 5%\displaystyle 5\% of the electric bulbs manufactured by a company are defective, use Poisson distribution to find the probability that in a sample of $100bulbs,\displaystyle bulbs,5$ bulbs will be defective. [Given : $e^{-5} = 0.007$ ]

Select Your Answer (Keyboard: A, B, C, D)
For any discrepancies in this question, email contact@cadada.in

Correct Answer

✅ Option a — $0.1823$

All Options:

  • A$0.1823$
  • B$0.1723$
  • C$0.1623$
  • D$0.1923$

Detailed Solution & Explanation

Let n=100\displaystyle n = 100 be the sample size, and let p=5%=0.05\displaystyle p = 5\% = 0.05 be the probability of a bulb being defective. The mean parameter m\displaystyle m for the Poisson distribution is: m=np=100×0.05=5m = np = 100 ×\displaystyle \times 0.05 = 5 We need to find the probability of exactly 5\displaystyle 5 defective bulbs, i.e., P(X=5)\displaystyle P(X = 5). The probability mass function of the Poisson distribution is: P(X=k)=e−mmkk!P(X = k) = e−mmkk!\displaystyle \frac{e^{-m} m^k}{k!} Substituting m=5\displaystyle m = 5 and k=5\displaystyle k = 5 into the formula: P(X=5)=e−5555!=e−5×3125120=e−5×62524P(X = 5) = \displaystyle \frac{e^{-5} 5^5}{5!} = \frac{e^{-5} ×\displaystyle \times 3125}{120} = e^{-5} ×\displaystyle \times 62524\displaystyle \frac{625}{24} Using the given approximation e−5=0.007\displaystyle e^{-5} = 0.007: P(X=5)≈0.007×26.04167≈0.1823P(X = 5) ≈\displaystyle \approx 0.007 ×\displaystyle \times 26.04167 ≈\displaystyle \approx 0.1823 This corresponds to Option A. Note: The source option key indicates Option D, but the correct mathematical calculation yields the probability as 0.1823, which is Option A. Hence, **Option A** is the correct answer.

About This Chapter: Theoretical Distributions

Paper

Paper 3: Quantitative Aptitude

Weightage

4-6 Marks

Key Topics

Binomial, Poisson, Normal Distribution

This chapter covers Binomial, Poisson, Normal Distribution and is part of Paper 3: Quantitative Aptitude in the CA Foundation exam.

View Official ICAI Syllabus

Exam Strategy Tip

This topic carries 4-6 Marks weightage. Focus on understanding core concepts rather than memorizing.

Key Concepts to Understand

More Questions from Theoretical Distributions

Ready to Master Theoretical Distributions?

Practice all 230 questions with instant feedback, earn XP, track your streaks, and ace your CA Foundation exam.

Start Practicing — It's Free