A battery manufacturer is interested in thelifetime of its products. Thirty batteries are tested until they fail. The times to failure (in hours) are given below.
41.3 21.1 35.6 13.5 4.2 15.8
5.5 5.8 33.6 18.6 24.3 18.1
3.5 8.4 4211 9.4 10.6 8.9 13.7 19.6 9.2 5.9 19.4 24.2 27.3 30.6 29.4 18.0 32.8 1.1.6
a) The manufacturer claims that 50% of its batteries last longer than 20 h. Describe how your graph shows
whether or not this is true.