Question

a thermometer measures temperature to the nearest 0.5°c. which measurement shows an appropriate level of precision for the thermometer?
a. 21.56°c
b. 20°c
c. 16°c
d. 16.0°c

Explanation:

Step1: Understand Precision Requirement

The thermometer measures to the nearest \(0.5^\circ\text{C}\), so the measurement should have a precision of one decimal place (since \(0.5\) is a tenth - like precision in terms of decimal places for this context, e.g., \(x.0\), \(x.5\) are valid).

Step2: Analyze Each Option

• Option A: \(21.56^\circ\text{C}\) has a precision to the nearest \(0.01^\circ\text{C}\), which is more precise than \(0.5^\circ\text{C}\), so it's not appropriate.
• Option B: \(20^\circ\text{C}\) has a precision to the nearest \(1^\circ\text{C}\), less precise than \(0.5^\circ\text{C}\) requirement.
• Option C: \(16^\circ\text{C}\) also has a precision to the nearest \(1^\circ\text{C}\), less precise than needed.
• Option D: \(16.0^\circ\text{C}\) has a precision to the nearest \(0.1^\circ\text{C}\) (or we can think of it as being able to represent values like \(16.0\), \(16.5\) etc. when rounded to the nearest \(0.5^\circ\text{C}\)). It is the only one with a precision that is at least as precise as \(0.5^\circ\text{C}\) (in fact, more precise but still appropriate as it can be rounded to the nearest \(0.5^\circ\text{C}\) correctly).

Answer:

D. \(16.0^\circ\text{C}\)