Math Is Fun Forum

George,Y

Member

Registered: 2006-03-12

Posts: 1,379

Turning Point frequency in an iid random series

Suppose we have identically distributed random numbers, which are independent to each other.
There is a saying that the turning points, each either larger or smaller than both its neighoring numbers, accounts for 2/3 of the sample size.

Can anyone prove it?

Thanks

---

X'(y-Xβ)=0