c Data to determine the shape of requirement distributions are lacking for most nutrients; therefore, symmetry is assumed unless there are data adequate to indicate otherwise.
dCV of the requirement is needed for the probability approach.
Figure 4-8 shows the same hypothetical (simulated) joint distribution of intakes and requirements for the group of individuals presented in Figure 4-2. The figure includes joint intake and requirement data from 3,000 people, with a mean intake of 1,600 units and a mean requirement of 1,200 units. As before, intakes and requirements are independent (i.e., individuals with higher intakes are not more likely to have higher requirements).
As discussed earlier, the proportion of the population with inadequate intakes could be obtained simply by counting the people who