A thermocouple probe is used to make temperature measurements of compressed air tank. Eighteen measurements of the temperature result in a mean value of 395 K with a sample standard deviation of 1.85 C. What is the random uncertainty of the temperature measurement at a 95% level of confidence?

In the user's manual for the probe, the manufacturer reports an accuracy (considered to be the manufacturer reported systematic uncertainty) of 1.5 K. If the probe was recalibrated before the eighteen measurements using a standard with an accuracy of 0.25 K, what is the resulting total uncertainty of the measurement of the tank temperature? Express all resulting uncertainties in units of K