Question

If 3% of the calculators produced by a certain manufacturer is known to be defective, in a lot of 300 calculators purchased from this manufacturer, we expect to see about ________ defectives, give or take _______ or so.

Answer 1

firstly, 3% of 300 = 9 thus, you expect 9 to be defective

when speaking about the acceptance range, you can usually (1 or 2)%

9 \[9\pm3 (ish)\]