18. Which of the following statements is INCORRECT?
(A) The number 1200 has two significant figures.
(B) The Q test is used to determine whether a suspected data point is an outlier in a small data set.
(C) Assuming a solution density of approximately 1.0 g/mL, 200 ppb Hg²⁺ is equivalent to 1.0 μM Hg²⁺.
(D) The F test is used to compare the variances of two data sets to determine whether they are significantly different.
(E) 0.4 (± 0.01) + 0.2 (± 0.02) + 0.1 (± 0.01) = 0.7 (± 0.04)