1 (If you don't know what these, are set them each to 0.5. 2  z is the value that specifies the level of confidence you want in your confidence interval when you analyze your data. 3  Typical levels of confidence for surveys are 95%, in which case z is set to 1.96. 4  E sets the accuracy of your sample proportions.
Tests and diagnosis discussion for Gallstones: Many gallstones, especially silent stones, are discovered by accident during tests for other problems. But when gallstones are suspected to be the cause of symptoms, the doctor is likely to do an ultrasound exam. Ultrasound uses sound waves to create images of organs.
If you have symptoms, a doctor will want to verify the presence of a gallstone in the common bile duct. He or she may use one of the following imaging tests: 1  transabdominal ultrasound (TUS): an imaging procedure that uses high-frequency sound waves to examine the liver, gallbladder, spleen, kidneys, and pancreas.allstones in the bile duct may not cause symptoms for months or even years. However, if the blockage becomes severe, you may experience the following: 1  abdominal pain in the upper or middle-upper abdomen. 2  fever. 3  jaundice (yellowing of the skin and eyes). 4  loss of appetite.