Interpolate and extrapolate from graphed/tabulated data.
Estimate a value between measured points or beyond them using the displayed pattern.
核心知识
Interpolation stays between measured points; extrapolation goes beyond them. Both use the pattern in the data, but extrapolation is less certain.
深入理解
When ACT Science asks you to estimate a value that is not written directly, first decide whether the estimate is inside the observed range or outside it.
- Interpolation: estimate between two nearby recorded values.
- Extrapolation: extend the pattern beyond the last recorded value.
- Reliability check: extrapolation can be reasonable, but it depends more heavily on the assumption that the pattern continues.
If the question asks for an estimate, choose the answer that fits the local pattern instead of demanding an exact measured number.
分步讲解
- Locate the two nearest recorded points around the requested value.
- Decide whether the estimate is interpolation or extrapolation.
- Use the nearby pattern to estimate the missing value.
- Reject answer choices that are outside the pattern shown by the data.
常见误解
- Treating an estimated value as if it must appear exactly in the table.
- Using a faraway point instead of the nearest relevant interval.
- Trusting extrapolation as strongly as a direct reading or interpolation.
示例解析
In Study 1, Table 2 shows that a reaction produced 24 mL of gas after 5 min and 32 mL after 7 min. If the pattern between those times is approximately linear, how much gas would the reaction most likely have produced after 6 min?
选择一个答案查看解析