Florida Teacher Certification Examinations (FTCE) Subject Area Practice Test

In estimating the population of Caucasian right-handed people, what is the best mental computation to use?

1. 0.5 x 0.8

2. 0.4 x 0.9

3. 0.6 x 0.9

4. 0.7 x 0.85

The correct answer is: 0.6 x 0.9

Estimating the population of Caucasian right-handed people involves calculating likelihoods or proportions that represent this demographic. In this context, multiplying the proportion of Caucasians in the population by the proportion of right-handed individuals gives a more accurate estimate. Choosing the multiplication of 0.6 by 0.9 implies that 60% of the population is Caucasian and that 90% of that group is right-handed. This would result in an estimate that reflects a reasonably high representation of both attributes, indicating a significant portion of the population being both Caucasian and right-handed. In contrast, the other calculations represent different proportions that may not provide as precise an estimate for this specific demographic. For instance, lower values such as 0.4 or 0.5 for Caucasians would suggest a smaller segment of the population, which might not align with known demographic distributions. Meanwhile, the choice of 0.7 by 0.85 would suggest a very high representation of both attributes, potentially overestimating the population of Caucasian right-handed people. Using 0.6 and 0.9 strikes a balance that reflects common estimates of these groups. This choice is especially effective in mental math as both factors are straightforward and lend themselves