In a group of 100 children, the mean weight of a child is 15 kg. The SD is 1.5 kg. Which one of the following is TRUE
Ans. is 'a' 95% of children weigh between 12 kg & 18 kg Mean = 15 kgSD= 1.5 kgAs we know that area between 1 standard deviation on either side of a mean will include approximately 68% of the value in distribution. So 68% of children will weigh between 13.5 & 16.5 kg. (15 +- 1.5)Area between two standard deviation on either side of mean will include approximately 95% of the values in distribution. So 95% children will weigh between two standard deviation i.e., between 12 and 18 (15 +- 3).99% of children will weigh b/w three SD ie between 10.5 and 19.5 kg (15 +- 4.5).
95% of all children weigh between 12 and 18 kg
95% of all children weigh between 13.5 and 16.5 kg
99% of all children weigh between 12 and 18 kg
99% of all children weigh between 13.5 and 16.5 kg