[EX09-155] In a large cherry orchard the average yield has been 4.35 tons per acre for the last several years. A new fertilizer was tested on 15 randomly selected 1-acre plots. The yields (in tons)

from these plots follow: 3.56 5.00 4.88 4.93 3.92 4.25 5.12 5.13 4.79 4.45 5.35 4.81 3.48 4.45 4.72 At the 0.05 level of significance, do we have sufficient evidence to claim that there was a significant increase in production? Assume yield per acre is normally distributed.