CFA Practice Question

There are 434 practice questions for this study session.

CFA Practice Question

The time it takes an auto mechanic to replace a carburetor is known to follow a normal distribution with a mean of 53 minutes and a standard deviation of 7.5 minutes. This means that ______
A. about 68% of the time it takes between 45.5 minutes and 53 minutes to replace a carburetor.
B. about 68% of the time it takes between 53 minutes and 60.5 minutes to replace a carburetor.
C. about 95% of the time it takes between 38 minutes and 68 minutes to replace a carburetor.
Explanation: 95% of the observations lie within μ +- 2 σ or (38,68).

User Contributed Comments 4

User Comment
mchu according to the notes, the empirical rule applies only to distributions when 95% of the data points fall within two standard deviations of the mean.
StanleyMo 68% of the observations fall within 1 standard .
95% of the observations fall within 2 standard .
99.7% of the observations fall within 3 standard
sagrr 68 1
95 2
99.7 3
!
NikolaZ 68% of the values fall within 1 standard deviation of the mean. And 95% of values fall within 1.96 standard deviations of the mean, not 2.
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