问题
填空题
设随机变量X与-X服从同一均匀分布U[a,b],已知X的概率密度f(x)的平方f2(x)也是概率密度,则b=______.
答案
参考答案:[*]
解析:
[分析]: 如果X~U[a,b],则-X~U[-b,-a],现X与-X同分布,故有a=-b,即X~U[-b,b)].
这时,[*]
f2(x)也是概率密度,有
[*]
设随机变量X与-X服从同一均匀分布U[a,b],已知X的概率密度f(x)的平方f2(x)也是概率密度,则b=______.
参考答案:[*]
解析:
[分析]: 如果X~U[a,b],则-X~U[-b,-a],现X与-X同分布,故有a=-b,即X~U[-b,b)].
这时,[*]
f2(x)也是概率密度,有
[*]
选词填空。 | |
2. Basketball _____ by a Canadian doctor _____ James Naismith. 3. He _____ in 1861. 4. The teacher _____ her class into four groups. 5. Can you help me to _____ the composition? 6. You must _____ a lot to become good at it. 7. It _____ you healthy. |