Basic statistics in business and economics / George W. Summers, William S. Peters, Charles P. Armstrong. Summers, George William. Peters, William Stanley, 1925- joint author. Armstrong, Charles P., joint author. Statistics. Social sciences Statistical methods. Commercial statistics. HA29 .S83 1977 519.5 SUB Includes index. Belmont, Calif. : Wadsworth Pub. Co., c1977. c1977. 1977 Text xv, 646 p. : eng