Dental In a class, the mean weight of 4 students is 90 kg and standard deviation is 30, then 95% confidence interval would be accordingly: A 60-80 B 30-150 C 60-120 D 70-110 💡 Explanation In a class, the mean weight of 4 students is 90 kg and standard deviation is 30, then 95% confidence interval would be accordingly: ✓ Correct Answer: B. 30-150