time = best estimate ± uncertainty

μ = \frac{∑_{i=1}^{N} x_{i}}{N}

σ = \sqrt{\frac{∑_{i=1}^{N} (x_{i} − μ)^{2}}{N − 1}}

time t = 4.25 ± 0.04 seconds distance L = 1.031 ± 0.017 meters