Herskovits consulted Group Health Hospital (GHH) (defendant), operated by Group Health Cooperative of Puget Sound (defendant), complaining of chest pain and coughing. Treating physicians at the GHH took a chest X-ray but did not perform any other tests. GHH treated Herskovits’s condition with a cough suppressant. Herskovits’s chest pain and coughing persisted, and he consulted Dr. Jonathan Ostrow for a second medical opinion. Ostrow diagnosed Herskovits with an advanced form of lung cancer. Herskovits underwent an operation to remove the cancerous lung but died 20 months later. Herskovits’s wife, as administratrix of his estate (the Estate) (plaintiff), filed a wrongful death suit against GHH. Ostrow testified for the Estate that had GHH’s physicians detected the cancer, Herskovits’s possibility of a five-year survival would have been 39 percent. Due to GHH’s failure to detect the cancer, Herskovits’s chance of survival was reduced to 25 percent. The Estate argued that the reduction in the chance of survival from 39 percent to 25 percent was sufficient evidence to allow a jury to consider the proximate cause issue. GHH argued that the Estate was unable to produce expert testimony that the delay in Herskovits’s diagnosis “probably” or “more likely than not” caused his death. The trial court granted GHH’s motion for summary judgment, and the Estate appealed.