In order to find what fraction describes this percentage, you first need to know that no matter what percentage you are working with, if you want to convert it into a fraction, put the 35 as the numerator and 100 as the denominator. If you still don't know what I mean, 35 at the top of the fraction and 100 at the bottom. Like this; 35/100. Then, you can simplify it by finding a common multiple between 35 and 100. For example, 5 can be divided into 35 and 100. 35 divided by 5 is 7 and 100 divided by 5 is 20. Your result is 7/20, which can further no more be simplified because there are no more common multiples between the two numbers.
The answer is 68 inches. The mean is the average, so you would need to add all the numbers (408), and divide by how many there are (6) which will give you 68.