experiment times: .15, .13, .16, .14, .15, .14, .15, .14

what is the the best estimate and estimate the uncertainty?

The uncertainty estimate would be the standard deviation or "sigma", which is the square root of the square of the average deviation from the mean. The mean is 0.145, and that is the "best estoiate".

Squared deviations are:
2.5*10^-5, 2.25*10^-4,2.25*10^-4,2.5*10^-5, 2.5*10^-5, 2.5*10^-5, 2.5*10^-5, 2.5*10^-5
Mean squared deviation: 7.19*10^-5
Standard deviation = 0.0085