Answer:
9:3:3:1
Explanation:
There are 420 kernels, over half of these are purple wrinkled (242/420=0.576) one fifth are purple smooth (84/420=0.2), just under one fifth are yellow wrinkled (70/420=0.167), and just over one twentieth are yellow smooth (24/420 = 0.057).
The ratio is 0.567: 0.2: 0.167: 0.057
0.567/0.057 = 9.9, so the ratio of purple wrinkled to yellow smooth is around 9:1.
0.567/0.2 = 2.835 and 0.567/0.167 = 3.39, so the ratio of purple wrinkled to purple smooth and yellow wrinkled is approx 3:1
0.2/0.057 = 3.5 and 0.167/0.057 = 2.92, so the ratio of purple smooth and yellow wrinkled to yellow smooth is approx 3:1
Therefore, the ratio is approximately 9:3:3:1.
This is a classic Mendelian ratio for a independent assortment associated with a dihybrid cross.
