I am too lazy I'll explain so you find 688 minus 267 then you divide the difference by 6 and then u subtract the difference from 267x100 because that will be the total. Then u find the mean of the 94 numbers u get!
4 Americans can arrange themselves in 4! ways.similarly ,3 Frenchmen can arrange themselves in 3! ways.3 Englishmen can arrange themselves in 3! ways.now these 3 groups of same nationality people can be arranged among themselves in 3! ways.so total number of ways = 3!4!3!3!
