MEEN 260
Introduction to Engineering Experimentation
T-CA03
Problem 1)
During this in-class activity, we will determine the confidence interval for the room temperature.
Task 1)
The instructor will place several temperature sensors in the room, and allow them
to come to equilibrium with the room temperature.
Task 2)
Collect temperature data from the sensors, and log these values in the table below.
Task 3)
Calculate the average measured temperature and the sample deviation.
Task 4)
Based on the number of measurements, determine whether you should use a ztable or t-table for your calculations.
Task 5)
Determine the confidence interval for the room temperature, assuming a
confidence level of 95%.
Value [℉]
Measurement #1
Measurement #2
Measurement #3
Measurement #4
Measurement #5
Measurement #6
Measurement #7
Measurement #8
Measurement #9
Measurement #10
Average Measurement, 𝑥̅
Sample Deviation, 𝑠𝑥
Number of Samples, 𝑛
Confidence Interval (? < 𝑇𝑟𝑜𝑜𝑚 <? )
Task 6)
73.86
77.43
78.83
74.38
73.5
74.51
76.34
75.55
2.017672
7
73.684 < T < 77.416
Most temperature sensors have a listed accuracy (i.e. maximum bias uncertainty)
of ±1℉ . What confidence level would result in a confidence interval of
approximately the same range? 80%
Note: Another way of asking this question is “What confidence level corresponds
to random uncertainty of the approximately the same value of the systematic
(bias) uncertainty?”