Genetics

Interphase takes the longest because this is where all chromosomes are being replicated. It takes a long time to make copies of the DNA to prepare for mitosis - this is why there are so many cells in interphase.

2000 : 320 : 150 : 80 : 120
25 : 4 : 1.875 : 1 : 1.5

According to some sources, about 90% of mitosis is spent in prophase, however, mitosis is only 8% of the total cell life. Thus, a cell spends about 7% of it's life in prophase. The cell spends most of it's life in Interphase. Interphase is 90% of the cell's TOTAL life span. From other sources, it is found that 24% of the cell's time was spent in prophase, 2% in metaphase, 4% in anaphase, and 9% in telophase. These numbers are based on an experiment that was done similar to your question. What you could also do is take each number, say 2000 and divide it by the number of cells observed (2000 + 320 + 150 + 80 + 120) and then multiplying it by 100% to get the actual percent.

Perhaps this site can help: http://classic.sidwell.edu/us/science/vlb/mitosis/

Reply back if you still need further assistance with this question.