An investigation of technician differences was conducted in the hematology laboratory of a large medical facility. In one portion of the investigation, blood specimens from seven donors were given to two laboratory technicians for analysis. Assume the data follows a normal distribution.

Sample Technician A Measurement Technician B Measurement 1.27 1.36 1.45 1.21 1.19 1.41 1.38 1.33 1.82 1.77 1.41 1.48 1.52 1.66

This data had sample mean difference and difference standard deviation ¯d = ?0.259 and sd = 0.134

(a) Explain why the data is not independent between samples.

(b) Calculate and interpret a 95% confidence interval for the mean difference in measurement between technician A and technician B

(c) Ideally, the two measurements should be the same - either a positive or negative mean difference is evidence of difference in measurement. Is there evidence of a mean difference in measurement? Answer using a hypothesis test with ? = 0.05