5) Cystic fibrosis is caused by a gene on chromosome 7 and results in the build-up of mucus in the lungs. Two parents who do not have cystic fibrosis have three children with the disease. What is the...

Extracted text: 5) Cystic fibrosis is caused by a gene on chromosome 7 and results in the build-up of mucus in the lungs. Two parents who do not have cystic fibrosis have three children with the disease. What is the probability that their fourth child will also have cystic fibrosis? Explain.