I’ll mark !
using symbols, diagram a cross that would give these results by completing the punnet square by placing the correct answers in their appropriate spot.
(purple smooth (pr)= 75, white smooth (pr)= 28, purple wrinkled (pr)= 24, white wrinkled (pr)= 8) *purple smooth is dominant, white wrinkled is recessive.

See attachment

Explanation:

There are 4 possible phenotypes: purple smooth, white smooth, purple wrinkled and white wrinkled.

We know that purple is dominant to white (P = purple, p = white). So PP = purple, Pp = purple, and pp = white.

We know that smooth is dominant to wrinkled (R = smooth, r = wrinkled). So RR = smooth, Rr = smooth and rr = wrinkled

If you had no idea where to start, you could start drawing up punnet squares with parents of random genotypes. However, the numbers are in a classic Mendelian ratio for a dihybrid cross (with heterozygous parents). That is, the nubmers are 75:28:25:8, which is roughly 9:3:3:1.

The possible genotypes are listed in the punnet square, which would give phenotypes of 9 purple smooth: 3 white smooth: 3: purple wrinkled: 1 white wrinkled