8. ASTM Standard E23 defines standard test methods for notched bar impact testing of metallic materials. The Charpy V-notch (CVN) technique measures impact energy and is often used to determine whether or not a material experiences a ductile-to-brittle transition with decreasing temperature. Ten measurements of impact energy (J) on specimens of A238 steel cut at 60°C are as follows: 64.1 64.7 64.5 64.6 64.5 64.3 64.6 Assume that the impact energy is normally distributed with σ= 1J. Find the 95% confidence interval for the mean (μ) impact energy. 64.8 64.2 64.3