Foundry marks

Figure 6-10. Foundry marks consist of embossed letters, numbers, or logos that manufacturers use to identify cast products.

The actual mean value obtained for the difference between the two types of pot was 18.1 The true value will lie 95% of cases 38.3 on either side of this, i.e. from — 20.2 to + 56.4 We thus see what a poor comparison is afforded by the data cited. There may well be marked differences between the foundries, but the present data is quite inadequate to answer these queries. 

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