Chứng minh rằng:
(2/1.3)+(2/3.5)+(2/5.7)+ ... + (2/97.99) > 98%

Astandard american eskimo dog has a mean weight of 30 pounds with a standard deviation of 2 pounds. assuming the weights of standard eskimo dogs are normally distributed, what range of weights would 99.7% of the dogs have? approximately 26–34 pounds approximately 24–36 pounds approximately 28–32 pounds approximately 29–31 pounds

Can any one me with the answers to these questions asap?

3382-299=3383- ? fill in the blank?