In: Math
1. Explain what it means for the normal distribution to be symmetrical about the mean?
2. Why is it important to know the mean and standard deviation for a data set when applying the empirical rule?
3. If we are focused on 68% of the normal distribution, what percentage of the distribution is left in the upper tail only?
4. What value separates the 50% of the distribution from the other 50% of the distribution?
(1)
The normal distribution to be symmetrical about the mean means the left side of the distribution mirrors the right side. It is a never a skewed distribution. It is unimodal.
(2)
It is important to know the mean and standard deviation for a data set when applying the empirical rule because the empirical rule requires the mean ad standard deviation as follows:
The empirical rule states that for a normal distribution, nearly all of the data will fall within 3 standard deviation of themean:
68% of data falls within first standard deviation from the mean.
95% of data falls within two standard deviation from the mean.
99.7% of data falls within three standard deviation from the mean.
(3)
If we are focused on 68% of the normal distribution percentage of the distribution is left in the upper tail only = (100- 68)/2 = 16%
(4) The value
= mean seperates the 50% of the distribution from the other 50% of
the distribution.