Scientists studied the occurrence of chromosomal non-disjunction during oogenesis in two different cohorts of women: Cohort A and Cohort B.
The total number of non-disjunction errors recorded in each cohort was:
The table below shows the percentage of these errors that occurred in the first meiotic division (MIMIMI) and the second meiotic division (MIIMIIMII).
| Cohort | Total errors | Percentage of errors in MIMIMI (%) | Percentage of errors in MIIMIIMII (%) |
|---|---|---|---|
| Cohort A | 380 | 75 | 25 |
| Cohort B | 650 | 28 | 72 |
A student concluded that there were more errors in MIMIMI in Cohort B than in Cohort A because Cohort B had a significantly larger total number of errors.
Using the data in the table and suitable calculations, show why this conclusion is not valid.