Could you please explain these so if I got a similar question I could answer. Thanks.

1. Suppose a group of scores has a mean of 40 and a standard deviation of 10. A score of 80 would equate to a standard score of:

2. Suppose that a test taker earned 125 raw score points on a vocabulary test where the normative sample averaged 100 points (with SD of 15 points). Suppose, in addition, he earned 110 raw score points on a spatial thinking test where the normative sample averaged 90 points (with SD of 20 points). In which skill area does he show greater aptitude, vocabulary or spatial thinking?

3. What is the relationship between the variance and the standard deviation?