Moving to another question will save this response. Question 6 Fixing a UCL and LCL at 3 standard deviations (take area as 99.73% ) means that the probability of making a Type 1 error is approximately: 0.135% for each tail (above or below the UCL and LCL, respectively)" 2.5% for each tail (above or below the UCL and LCL, respectively) "99.7\% for each tall (above or below the UCL and LCL, respectively)" r. 0.30% for each tail (above or below the UCL and LCL, respectively)