Hi Sample: n = 15 , mean = .68, sd = .08 Ho: u = .70 (claim) Ha: u < .70 ------------------ t(.68) = (.68 -.70)/[.08/sqrt(15)] = -.0645 p-value = P( t< -.0645 when df = 14) = .47 Since the p-value is greater than 5%, fail to reject Ho. Conclusion: The claim is reasonable at the 5% confidence level. Wish You the Best in your Studies.