the average yield of soybeans in Ohio is 58 bu/ Acre (the control mean). a company has developed a new microbial based soil additive that they believe will increase yields. We wish to test whether a field that has been treated with the product has soybean yields that are different than 58 bu/acre. We are going to study with 49 fields and set up the hypothesis at a=.05. After we conduct the experiment we get a sample mean x=60 bu/acre and s=7 bu/acre. The test shows

Z=___________