Question

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 fuel). Random samples of 32 blended fuels are tested in a lab to ascertain the bio/total carbon ratio. (a) If the true mean is .9130 with a standard deviation of 0.0040, within what interval will 98 percent of the sample means fall? (Round your answers to 4 decimal places.)

The interval is from --?-- to---?--

Answer 1

As the sample size here is 32 > 30, therefore the central limit theorem is valid and the distribution of the sample means here is given as:

From standard normal tables, we have:
P(Z < 2.326) = 0.99

Therefore, P( - 2.326 < Z < 2.326) = 0.98

Therefore the confidence interval here is obtained here as:

This is the required confidence interval here.