I need help with number 2 please

Suppose a man is heterozygous for heterochromia, an autosomal dominant disorder which causes two different‑colored eyes in an individual, produced 25‑offspring with his normal‑eyed wife. of their children, 15 were heterochromatic and 10 were‑normal. calculate the chi‑square value for this observation.

A. 127 cm^2 b. 144.5 cm^2 c. 172 cm^2 d. 50 cm^2

45 was divided by a power of ten to get 4.5. what power of ten was it divided by? people 4.5