[Solved] An investigation of the effectiveness of a training program to improve customer relationships included a pre-training and a post-training customer survey. To compare the differences they computed (post-training survey score − pre-training survey score). Seven customers were randomly selected and completed both surveys. The results are shown here. For a 0.05 significance level,what is the decision regarding the hypothesis that the training was effective in improving customer relationships? A)Reject the null hypothesis and conclude that the training was effective. B)Reject the null hypothesis and conclude that the training was ineffective. C)Fail to reject the null hypothesis and conclude that the mean survey scores are the same. D)Fail to reject the null hypothesis and conclude that the mean survey scores are not equal. Iris Diaphragm: A part of the microscope that adjusts the size of the aperture, controlling the amount of light passing through the specimen. Stereomicroscope: A type of microscope designed for low magnification observation of a sample using light reflected from the surface of an object rather than transmitted through it. Dissecting Microscope: A type of light microscope designed for low magnification observation of a sample, commonly used for dissection. Compound Light Microscope: An optical instrument that uses visible light and a system of lenses to magnify small objects or details not visible to the naked eye.