2Value of products less cost of materials, supplies, fuel, electric energy, and contract work.

3The percentage standard errors shown in this column indicate the difference that can be expected between the estimates and comparable complete canvass totals, because of sampling fluctuations. The estimates will differ from the complete totals by less than:

(1) The percentage shown: approximately 2 times out of 3

(ii) Twice the percentage shown: approximately 19 times out of 20
(iii) Three times the percentage shown: almost always

The Annual Survey estimates for industry group 24, "Lumber and wood products, except furniture," tend to be understated because of incomplete coverage of logging camps and logging contractors not operating sawmills (Standard Industrial Classification Industry 2411). This undercoverage is estimated at less than 5 percent.

Chapter III: SHIPMENTS. METALS, FUELS, AND INVENTORIES

are

Table 1.-VALUE OF SHIPMENTS, BY SELECTED CLASSES OF PRODUCTS, FOR THE UNITED STATES: 1950, 1949, AND 1947 (In Column (A), the first four digits of the 5-digit code refer to the industry (as defined in the Standard Industrial Classification system) in which the class of products is primarily classified. The fifth digit refers to the Census Bureau code assigned to a specific group of products. In Columns (C), (D), and (E), the values total shipments of the product classes described. For the most part, the 1950 and 1949 values are estimates derived from the sample Annual Survey of Manufactures and are qualified by the sampling variation (in percent) shown in Columns (F) and (G). Where the 1950 or 1949 values are other than Annual Survey estimates, letter symbols appear in Columns (F) or (G). The reference list of sources appearing at the end of the release is keyed to these letters. The 1950 and 1949 estimates may be understated to a slight degree by the omission of data for reported product class combinations of low value which could not be allocated to the appropriate product classes.) (Value figures in thousands of dollars)

Table 1.--VALUE OF SHIPMENTS, BY SELECTED CLASSES OF PRODUCTS, FOR THE UNITED STATES: 1950, 1949, AND 1947--Continued (Value figures in thousands of dollars)

Table 1.-VALUE OF SHIPMENTS, BY SELECTED CLASSES OF PRODUCTS, FOR THE UNITED STATES: 1950, 1949, AND 1947---Continued (Value figures in thousands of dollars)

All other rolled, drawn, and extruded copper and copper-base

Table 1.-VALUE OF SHIPMENTS, BY SELECTED CLASSES OF PRODUCTS, FOR THE UNITED STATES: 1950, 1949, AND 1947--Continued (Value figures in thousands of dollars)

pumps

water systems

88,196 15 158,965 56,693

r