Answer:
The correct option is 3. The mean of normal distribution is 4.
Explanation:
Some specification of normal distribution graph:
1. The graph of normal distribution is a bell shaped curve.
2. It is described with the help of mean and standard deviation.
3. It is symmetrical about its mean.
From the given graph it is clear that the value of distribution is maximum at 4 and it symmetrical about 4.
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Therefore the mean of normal distribution is 4 and option 3 is correct.