help plz

You want to define control limits, UCL and LCL, for a X-bar Chart to control the diameter of cylinder rails. You collected 30 samples from the manufacturing line. Each sample is of size 7. Assume that X is 3.311 inches and R is 8.503 inches. Then, UCL is inches and LCL is inches for this chart. Round a decimal number to two decimal places. For example, 1.73620397 can be rounded to two decimal places as 1.74. As another example, 1.34412 can be rounded to two decimal places as 1.34