Hi there! So 39,300 copies of a book were sold on debut month of release, and that represents 6.3% of all copies sold to date. To find the total amount of copies sold, we can write and solve a proportion. Set it up like this:
39,300/x = 6.3/100
We set it up like this because 39,300 is part of the total amount, and it represents 6.3% of the total book sales. Percents are parts of 100, which is why 6.3 is above 100. Let's cross multiply the values. 39,300 * 100 is 3,930,000. 6.3 * x is 6.3x. that makes 3,930,000 = 6.3x. Divide each side by 6.3 to isolate the x. 6.3x/6.3 cancels out. 3,930,000/6.3 is 623,809.5238 or 623,810 when rounded to the nearest whole number. There. The total amount of copies sold to date is about 623,810.
4(r)^x=y
4(r)^(1)=2
r=1/2
y=4*(1/2)^x
You need to change 17% to decimal by moving the decimal to the right by 2x
so you will get .17*800=136
