Answer:
The given sequence is geometric sequence
In the given pattern we have next number is 
Step-by-step explanation:
Given numbers are 64,-16,4,-1
To identify the pattern of the given numbers :
Let
,
,
and 
To find the next number that is 
common ratio 





Therefore the common ration is 
Therefore the given sequence is geometric sequence
The nth term of the geometric sequence is 
Now find the 5th term so put n=5 ,
we have





Therefore 