I am not sure what you mean by your first question. However, see the histogram and other descriptive statistics. Thanks so much for your help!
I am looking up the Welch test. I don't recall learning about that!
Well, what I was alluding to was that scores can be percentages, which are bound between 0 and 1.00. If all of the scores were high (e.g. .90's but there was quite a bit of variability, your standard deviation may not represent the data coverage symmetrically. Say your mean = 95% and std = 10%.