A new method for the determination of mercury in oyster tissue is compared with NIST SRM 1566B (Oyster tissue). The NIST standard is said to contain 0.0371 mg/kg mercury in oyster tissue. Five replicates through the new method gave a mercury content of 42 ppb with a standard deviation of 2 ppb.
Perform a t-test at the 95% confidence level to determine if the new method contains bias.
a) What is the calculated value of t for the new method (to two sig. figs)?
b) What is the critical value of t (to two sig. figs)?