concerns about climate change and CO2 reduction have initiated the commercial production of blends of biodiesel (e.g. from renewable sources) and petrodiesel (from fossil fuels). Random samples of 47 blended fuels are tested in a lab to ascertain the bio/total carbon ratio.

a) If the true mean is .9560 with a standard deviation of 0.0080, within what interval will 99 percent of the sample means fall?