A particular counting system has a stable average background rate (measured over a long time) of 45 counts/min. A decaying radioisotope source was introduced and a 10-min count showed a total of 1752 counts. After a delay of 24 h, the 10-min count was repeated, this time giving a total of 832 counts.

 (a) What is the half-life of the source?

 (b) What is the expected standard deviation of the half-life value due to counting statistics?