Comparing order of magnitude a biologist estimated the number of cells in a culture sample as 1.3 × 102. one week later, he looked at the same culture sample and estimated that the number of cells had grown to 3.9 × 105. determine how many times larger the culture sample was compared to a week earlier. (3.9 × 105) (1.3 × 102) complete the quotient in scientific notation and find the solution in standard notation. × =