<prompt> Lead aprons of ___ mm will reduce the intensity of scattered X -rays over ___ per cent and should be worn by all workers regularly associated with X-ray procedures.0.2 and 600.3 and 700.4 and 800.5 and 90  <response>: Lead aprons of 0.5 mm will reduce the intensity of scattered X -rays over 90 per cent and should be worn by all workers regularly associated with X-ray procedures. 