study_hours = [10, 12, 14, 16, 18]
mean = sum(study_hours) / len(study_hours)
squared_diffs = [(hours - mean) ** 2 for hours in study_hours]
population_variance = sum(squared_diffs) / len(study_hours)
print("Mean:", mean)
print("Population variance:", population_variance)
# Mean: 14.0
# Population variance: 8.0