I need the answer of this question with steps aslo rounded yo 4 decimal places and put the units..it's a biostats class

3. (10 points) Blood coagulation and clot formation in humans is a complicated process with at least 13 different plasma coagulation factors involved. One of the more impor- tant protein factors is called prothombin, which must be converted into the enzyme thrombin for coagulation to occur. Individuals with vitamin K deficiency are thought to have low prothombin levels as a result. Twenty patients with vitamin K deficiency were randomly chosen and their prothrom bin levels were measured. The mean prothrombin level for the sample was 20 mg/100 ml and the variance was 121 (mg/100 ml)2. Note: the 100 ml is just the unit and not part of the mean or variance. Calculate a 90% confidence interval for the true mean prothrombin in vitamin K deficient patients