看图分析回答：

小冰学习虽然很努力，但成绩总是不理想。妈妈总是批评他玩心重，小冰很委屈，同妈妈大吵了一架。对此，下列观点正确的是（  ）

    Hello. I'm a green monster(怪物). I have a big head. I have one big eye and one big mouth. I have no nose. I have two arms and two legs. This is my friend. He is a monster(怪物), too. He is blue. He has a big body. He has two long arms and two strong legs. He has a long tail. We are very kind.

根据上面短文的意思判断下面的句子是否正确。

已知正态分布密度曲线 ,且 ,则方差为____.