First we need to determine the fraction of a second that the computer can perform 1,000 operations. We compute this as 4.5x10=45^-6=0.00000000012. Thus, the computer performs 1,000 operations every 0.00000000012 seconds. Now we need to determine how many of these periods are in an hour. An hour is 60x60=3,600 seconds. Now we divide 3,600 seconds by 0.00000000012 and get 29,893,556,250,000 times per hour that the computer can perform 1,000 operations. So multiply the 29,893,556,250,000 by 1,000 operations and we get 29,893,556,250,000,000 operations in an hour, or, in scientific notation, 2.99 x 10^16.