- CFA Exams
- 2021 CFA Level I Exam
- Study Session 3. Quantitative Methods (2)
- Reading 9. Common Probability Distributions
- Subject 8. The Standard Normal Distribution

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**CFA Practice Question**

The daily sales at a certain shop follow a normal distribution with a mean of $1,060 and a standard deviation of $310. What is the probability that the daily sales are less than $409?

B. 0.4821

C. 0.5179

A. 0.0179

B. 0.4821

C. 0.5179

Correct Answer: A

The z-value corresponding to $409 is computed as: z = (409 - 1060)/310 = -2.10. From z-table P(Z <= -2.10) = 0.0179, P(Sales <= 409) = 0.0179.

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**User Contributed Comments**
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User |
Comment |
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Rotigga |
(409-1060)/310=-2.1 So we know this is between 95% and 99% CI (1.96 and 2.58 respectively). Which means left tail is between 2.5% and 0.5%. The only answer in that range is A (0.0179) which is correct. |