Significant figures defined interval

It is very important to report the results of analyses in ways that are readily and unambiguously understood. The methods used to determine average values, standard deviations, confidence intervals, uncertainties etc. must be clearly defined. In some application areas, the concept of a reporting limit is useful it is stated that the concentration of the analyte is not less than a particular value. Prudence indicates that this limit should be greater than the limit of detection (see Section 2.3). Use of an appropriate number of significant figures is also critical in reporting results, as this indicates the precision of the measurements. 

Comprehensive reviews of energy sources are pubflshed by the World Energy Conference, formerly the World Power Conference at six-year intervals (83). The 1986 survey includes reserves and also gives total resources. In 1986 the total proven reserves of recoverable soHd fuels were given as 6 X 10 metric tons. One metric ton is defined as 29.2 x 10 MJ (27.7 x 10 Btu) to provide for the variation of calorific value in different coals. The total estimated additional reserves recoverable and total estimated additional amount in place are 2.2 x 10 and 7.7 x 10 metric tons, respectively. These figures are about double the 1913 estimates, primarily because significantly increased reserves have been indicated for Russia. 

Figure 5. Data from the literature (56, 80, 99, 164, 195, 220, 222, 223, 243) indicate that diffusive fluxes of sulfate (calculated from 40 pore-water profiles measured with pore-water equilibrators) are linearly related to concentrations of sulfate in the overlying lake water. The correlation is significant (p < 0.05) both with (r2 = 0.991) and without (r2 = 0.42) the two lakes with high sulfate concentrations. The strong correlation suggests that variations in the depth interval within which sulfate is consumed and in the minimum sulfate concentration defining the gradient are relatively unimportant in determining the flux, compared to variations in sulfate concentrations defining the upper end...

Figure 26.3 Percent of total days with estrous cytology in SD female rats fed atrazine in the diet. (Vaginal cytology was monitored daily for 14-day intervals, followed by 14 days of rest. Estrous cytology was defined by the presence of a majority of keratinized (cornified) cells in the lavage. Each point represents the mean S.E. of 60 animals per dose group. The mean responses to 400ppm at 13-14, 17-18, 21-22, and 25-26 weeks were significantly different from controls (ANOVA, p <. 05) other mean values were not significantly different.)...

PARTICIPATION, VESTING, ELIGIBILITY, AND SERVICE. Three significant dates and an interval figure in defined-benefit pension plans. 

Figure 2. Median and 95% confidence interval for radiocesium concentration in soil derived from the Chernobyl accident (squares, left v-axes) and weapons test (circles, right y-axes). Groups followed by the same characters are not significant different ( /-test, P > 0.05). Hollows (1) are defined where at least three from definite measured four points within a 3 m radius have a significantly higher altitude (> 10 cm) than the sampling plot, collines (3) are defined where at least three points have a significant lower altitude (> 10 cm) than the sampling plot. Plots which are not defined in that way (more or less on the same level) are grouped in class 2. N = 30 for each class, 10 points are excluded due to missing measurements within a 3 m radius.

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