A political pollster randomly selects a sample of 100 voters each day for 8 successive days and asks how many will vote for the incumbent. The pollster wishes to construct a p chart to see if the percentage favoring the incumbent candidate is too erratic.

ITEM	Number Favoring
TITLE	Incumbent Candidate
1	57
2	57
3	53
4	51
5	55
6	60
7	56
8	59

Referring to the problem statement, what is the numerical value of the upper control limit for the p chart?