Quantitative Literacy Practice Exam 2026 – Comprehensive Preparation Guide

A standard deviation of 11.78 inches indicates a significant degree of variability in the rainfall amounts. The standard deviation is a statistical measure that quantifies the amount of variation or dispersion in a set of data values. In this case, a higher standard deviation suggests that the rainfall amounts are spread out over a wide range, meaning that some measurements are much higher or lower than the mean value.

This variability is important because it tells us that rainfall amounts can fluctuate considerably from one period to another. A standard deviation of 11.78 inches implies that while there may be an average amount of rainfall, the actual values can deviate substantially from this average, indicating a lack of consistency in rainfall patterns. Consequently, this reinforces the idea that the rainfall amounts vary significantly, which is the crux of the chosen answer.

In contrast, the other options imply a degree of uniformity, predictability, or unreliability that does not align with a high standard deviation value, which clearly reflects a broad range of rainfall levels rather than stability or predictability.