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The following HTML text is provided to enhance online readability. Many aspects of typography translate only awkwardly to HTML. Please use the page image as the authoritative form to ensure accuracy. daily intakes for an individual are typically not available to reliably estimate the day-to-day variability, the pooled day-to-day SD of intake from CSFII (see Table B-2, Table B-3, Table B-4 through Table B-5) or from NHANES is used. The z-statistic is constructed as follows: z = By rearrangement, this can also be expressed as: z = (observed mean intake − AI) / (SD of daily intake/ The z-statistic is then compared to tabulated values (a selection of which are presented in Table B-6), to decide whether the desired level of accuracy is achieved when stating that the usual intake is larger than the AI. For example, consider a nutrient such as calcium with an AI of 1,000 mg /day, and suppose that the SD of daily intake from CSFII for the appropriate life stage and gender group is 325 mg/day. TABLE B-6 Selected Values of z and the Associated Level of Confidence When Concluding That Individual Usual Intake Is Larger Than the Adequate Intake (AI) or Less Than the Tolerable Upper Intake Level (UL)
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× (observed mean intake − AI)/SD of daily intake.