Final answer:
To ensure that 95% of all temperature readings from a thermocouple are within 0.5° of the actual temperature, the value of the standard deviation (σ) needs to be 0.25°.
Step-by-step explanation:
To ensure that 95% of all temperature readings from a thermocouple are within 0.5° of the actual temperature, the value of the standard deviation (σ) needs to be calculated.
We know that there is a 95% chance that the true population mean value (μ) is between two standard deviations from the sample mean. In this case, we want the interval to be 0.5°, so we can set up the following equation:
2σ = 0.5°
Solving for σ, we get:
σ = 0.5° / 2 = 0.25°
Therefore, the value of σ needs to be 0.25° to ensure that 95% of all temperature readings are within 0.5° of the actual temperature.