11-2. A medical researcher carefully measures the length of the fetal

humerus in 50 ultrasound studies by using electronically generated

distance-measuring “calipers” on the display. The researcher

obtains a mean value of 5.5 cm with a standard deviation of 2 mm.

After the measurements have been obtained, the researcher discovers

through studies of excised bone that the electronically

generated caliper measurements are consistently 2% larger than

the true length.

a. Describe the researcher’s original results in terms of bias, precision,

and accuracy.

b. How can the mean and standard deviation of the original data

be corrected?