I have some statistical backgroung but I'm nowhere near an expert so everything I tell you should be taken with a grain of salt. Here is what I think :
I believe your graph for the cumulative probability density function will look like this:
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While the probability density functiun must look like this:
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The Median is the value for which you have 50% above and 50% under, so here it would be 8.
The risk of damage equal or more to 6 could be 60% if you look at the graph, but I think it should actually be 75% considering you suppose to also include the probabilty the damage will be equal to 6 (so add 15%)
The Mean is basically the value ponderated by their frequency so 8.7 ? (2x0.05 + 4x0.2 + 6x0.15 + 8x0.1 + 10x0.05 + 12x0.35 + 14x0.1)
The standard deviation then would be 3.8 so everything between 4.9 and 12.5 (R million) would fall within one standard deviation from the mean.
For the percentage of the population falling within I'm not really sure but I would say 65% (thats the cumulative percentage of the values between 6 and 12 wich are the closest full values of 4.9 and 12.5 in your dataset)
I really hope this helped (then again please check everything I told you, I'm not at all sure and I do not want you to fail a test because of me )