Why don’t noble gases have a value for electronegativity?

1. they only form compounds with metals

2. they only form compounds with non-metals

3. they are gases

4. they have a full octet of valence electrons

The ages of personnel in the accounting department of a large company are normally distributed with a standard deviation of 7 years. there is a 0.02275 probability that the age of any randomly chosen person in the department is less than 22 and 0.15866 probabilty that the age of any randomly chosen person is greater than 43. what is the mean of this distribution?