Estimate Standard Deviation and Mean from distribution

[susumandrai]

I know what standard deviation means and how to find it using calculator and formula (frequency table).
But, given a distribution, I can not estimate it nor the mean.

Please help me to estimate the mean and standard deviation from the sample shown below:

 

[thepillow]

I know what standard deviation means and how to find it using calculator and formula (frequency table).
But, given a distribution, I can not estimate it nor the mean.

Please help me to estimate the mean and standard deviation from the sample shown below:
View attachment 2181

Often, a helpful way to think about the mean is that it's simply what you would expect (formally, the "expected value") if you were to randomly pull one of the data points from the distribution. The distribution in the picture looks like it is (roughly) symmetric around a certain value. In plain english (which I often prefer to the more formal jargon), it seems like you could draw a vertical line right down the middle of it and have about half of the data on either side. So if you were to randomly pull one of the points out of the distribution, where would you wager that it from come from?

Hopefully that will get you on the right track but if that's confusing definitely let me know.

 

[tkhunny]

Rule of Thumb for a distribution in the neighorhood of Normal. Standard Deviation is well-approximated by Range/6.