Stereograms appear to be composed entirely of random dots. However, they contain

separate images that a viewer can "fuse" into a threedimensional (3D) image by staring at the dots while defocusing the eyes. An experiment was performed to determine whether knowledge of the form of the embedded image affected the time required for subjects to fuse the images. One group of subjects (group NV) received no information or just verbal

information about the shape of the embedded object. A second group (group W) received both verbal information and visual information (specifically, a drawing of the object). The experimenters measured how many seconds it took for the subject to report that he or she saw the 3D image. 2-Sample t-interval for 1 - 2 df = 70 Conf level = 90% (NV) - (W) interval: (0.55, 5.47).

a) Interpret your interval in context.

b) Does it appear that viewing a picture of the image

helps people "see" the 3D image in a stereogram?