A certain length measurement is made with the following results:
Reading: 1 2 3 4 5 6 7 8 9 10
x, m: 12.54 12.73 12.44 12.51 12.52 12.84 12.49 12.67 12.55 12.53
Calculate the uncertainty level under a 99% of confidence, and the probability that a single measurement will be between 12.5m and 12.6m.