The police chief selects a sample of 49 local police officers from a population of officers with a mean physical fitness rating of 72 ± 7.0 (u ± o) on a 100-point physical endurance rating scale. He...

Extracted text: The police chief selects a sample of 49 local police officers from a population of officers with a mean physical fitness rating of 72 ± 7.0 (u ± o) on a 100-point physical endurance rating scale. He measures a sample mean physical fitness rating on this scale equal to 74. He conducts a one-independent sample z test to determine whether physical endurance increased at a .05 level of significance.