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NASA Cost Estimating Handbook v4 Table C-5: linear CER for a storage tank
| Tool | Cost Estimating |
| Source | National Aeronautics and Space Administration (2015). NASA Cost Estimating Handbook, Version 4.0. NASA Headquarters, Washington, DC. Appendix C, Table C-5, pp. C-14 to C-20. |
| Level | Undergraduate |
Problem
Ten storage tanks have weights (tons) and first-unit costs ($K) of (1.0, 6), (1.5, 11), (2.0, 14), (1.8, 16), (1.9, 20), (2.5, 18), (3.0, 22), (3.4, 30), (3.7, 26) and (3.9, 31). Fit a linear cost estimating relationship of cost on weight, report its fit statistics, and estimate the first-unit cost of a 2.2-ton tank with a 90 % prediction interval.
Inputs to Enter
- CER data (loaded by default): the ten weight, cost pairs
- Driver value 2.2 tons; 90 % prediction interval
Answers
- Slope b1 = 7.751392, intercept 0.26 as printed (0.2541 unrounded; the handbook rounds the slope to 7.75 first); predicted cost at 2.2 tons 17.31 $K
- R² = 0.8957 (printed 0.90), R = 0.948, SE = 2.77, CV = SE/Ȳ = 0.14
- t on the slope 8.287; 90 % prediction interval 11.87 to 22.74 $K (half-width 5.43 with t_0.95,8 = 1.860)
Notes
The tool's default CER data and driver value are this example; press Submit. A power-law CER is fitted to the same data alongside.