A manufacturer of electronics kits has found that the mean time required for novices to assemble its new circuit tester is 3 hours, with a standard deviation of 0.20 hours. A consultant has developed a new instructional booklet that he claims will reduce the time an inexperienced kit builder will need to assemble the device. In a test of the effectiveness of the new booklet, 15 novices require a mean of 2.90 hours to complete thejob. Assuming the population of times is normally distributed, and using the 0.05 level of significance, should we conclude that the new booklet is effective