I need help with my statistics homework

Question

If babies' weights are normally distributed with a mean of 3.23 kg and a standard deviation of 0.87 kg, find the range of weights that contain approximately

(a) 68% of the data

 kg --  kg

(b) 95% of the data

 kg --  kg 

(c) 99.7% of the data

 kg --  kg

Answer 1

mean 3.23 Kg standard deviation 0.87 kg

Per the Empirical Rule:

68% of data within 1 standard deviation of mean, so range is 3.23 +/- 0.87 kg

95% of data within 2 standard deviations of mean, so range is 3.23 +/- 2*0.87 kg

99.7% of data within 3 standard deviations of mean, so range is 3.23 +/- 3*0.87 kg