A manufacturer claims that a model of electric scooter has a battery charging time of 150 minutes (i.e. 2.5 hours). In order to test this claim, 22 electric scooters of that model were charged from empty to full battery. The length of time for each scooter to charge fully was recorded in minutes. The results are summarised in Table 2.

Table 2 Summary statistics for the batter}r charging time (in minutes] of a model of electric scooter Sample size Mean Standard deviation 22 161 29