【单选题】设X服从二项分布B(n,p),则有( ).
【单选题】----Why are you so _______,Amy? ----I thought I lost my purse, but I didn’t. I found it in my study!
【单选题】- Why are you so ______, Helen? - I thought I had lost my purse, but I didn’t. I found it in my study!
【简答题】I lost my bag the day before, but it ______ (find)now.
【单选题】设服从二项分布B~(n,p)的随机变量ξ的期望和方差分别是2.4与1.44,则二项分布的参数n、p的值为( )
【单选题】---Why are you so _______,Amy? ---I thought I lost my purse, but I didn’t. I found it in my study!