The French and Indian War began in 1754 and ended with the Treaty of Paris in 1763. The war provided Great Britain enormous territorial gains in North America, but disputes over subsequent frontier policy and paying the war's expenses led to colonial discontent, and ultimately to the American Revolution.
The next number is 7 times the first, so 7x. Therefore the first number is 45, the second number is 7(45) or 315, and the third number is 100 + 45 to 145.