A study of long-distance phone calls made from General Electric Corporate Headquarters in Fairfield, Connecticut, revealed the l
ength of the calls, in minutes, follows the normal probability distribution. The mean length of time per call was 4.3 minutes and the standard deviation was 0.50 minutes. What is the probability that calls last between 4.3 and 5.0 minutes?
1 answer:
Answer:
41.92%
Step-by-step explanation:
In table attached standard normal distribution curve is shown.
Data
mean, µ = 4.3 minutes
standard deviation, σ = 0.5 minutes
desired point, x = 5 minutes
x-axis, Z = (x - µ)/σ
The probability that calls last between 4.3 and 5.0 minutes is equivalent to find the area below the curve between Z = 0 and Z = (5 - 4.3)/0.5 = 1.4, which is 0.4192, or 41.92%
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