12.58 The set of activities and decisions through which a firm moves from its initial awareness of an innovative industrial procedure to its final adoption or rejection of the innovation is referred to as the industrial adoption process. The process can be described as having five stages:

(1) awareness, (2) interest (additional information requested), (3) evaluation (advantages and disadvantages compared), (4) trial (innovation tested), and (5) adoption. As part of a study of the industrial adoption process, S. Ozanne and R. Churchill (1971) hypothesized that firms use a greater number of informational inputs to the process (e.g., visits by salespersons) in the later stages than in the earlier stages. In particular, they tested the hypotheses that a greater number of informational inputs are used in the interest stage than in the awareness stage and that a greater number are used in the evaluation stage than in the interest stage. Ozanne and Churchill collected the information given in Table 12.17 on the number of informational inputs used by a sample of 37 industrial firms that had recently adopted a particular new automatic machine tool.

a Do the data provide, sufficient evidence to indicate that differences exist in the mean number of informational inputs of the three stages of the industrial adoption process studied by Ozanne and Churchill? Test by using 0.05.
b Find a 90% confidence interval for the difference in the mean number of informational inputs between the evaluation and awareness stages.