Before determining the amount of Na2CO3 in a sample, you decide to
check your procedure by analyzing a sample known to
be 98.76% w/w Na2CO3. Five replicate determinations
of the %w/w Na2CO3 in the standard gave the
following results.
98.71% 98.59% 98.62% 98.44% 98.58%
Using α = 0.05, is there any evidence that the analysis is
giving inaccurate results?​