Bud N. Chemist must determine the density of a mineral sample. His four trials yield densities of 4.77 g/cm3 , 4.67 g/cm3 , 4.69
g/cm3 , and 4.81 g/cm3 . Independent studies found the correct density to be 4.75 g/cm3 . Which of the following statements represents the best analysis of the data? A) Bud's results have much greater accuracy than precison B) Bud's results have much greater precision than accuracy C) Bud's results have high accuracy and high precision D) Bud's results have low accuracy and low precision E) Bud's equipment is faulty
PRECISION AND ACCURACY ARE TERMS THAT ARE USED TO INDICATE THE QUALITY OF A GIVEN SET OF STATISTICAL OBSERVATIONS.
WHILE PRECISION TALKS ABOUT THE LEVEL OF AGREEMENT AMONGST THE SAME SET OF DATA OBSERVATIONS, ACCURACY TALKS ABOUT HOW FAR OR HOW CLOSE THE TRUE VALUE IS TO THE CALCULATED VALUE. TAKING AN AVERAGE OF ALL THE VALUES, IT STANDS AT 4.735 WHICH IS QUITE CLOSE TO THE TRUE VALUE OF 4.75
NOW, LOOKING AT THE SPREAD OF THE VALUES IN THE OBSERVATION, WE CAN SEE THAT THESE VALUES ARE QUITE NOT CLOSE TO EACH OTHER. HENCE, WE CAN CONCLUDE THAT ALTHOUGH HIS OBSERVATIONS ARE QUITE QUITE ACCURATE BASED ON THE OVERALL AVERAGE, WE CAN CONFIDENTLY POSIT THAT HIS VALUES HAVE A LOW LEVEL OF PRECISION
