Question

Organic chemists often purify organic compounds by a method known as fractional crystallization. An experimenter wanted to prepare and purify 4.85 g of aniline. Ten 4.85 g quantities of aniline were individually prepared and purified to acetanilide. The following dry yields were recorded. 3.83 3.81 3.89 3.87 3.90 3.37 3.63 4.01 3.70 3.82

Estimate the mean grams of acetanilide that can be recovered from an initial amount of 4.85 g of aniline. Use a 95% confidence interval. (Round your answers to three decimal places.)

Answer 1

We have given that,              
              
Sample mean =3.783      
Sample standard deviation =0.1793  
Sample size =10      
Level of significance=1-0.95=0.05      
Degree of freedom =9      
              
t critical value is (by using t table)=   2.262      
              
Confidence interval formula is               


=(3.655,3.911)          
              
              
Lower confidence limit=3.655      
              
Upper confidence limit=  3.911