TABLE 18-2
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.
-Referring to Table 18-2,what is the numerical value of the upper control limit for the p chart?
A)0.92
B)0.89
C)0.71
D)0.62

Question

TABLE 18-2
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. 
-Referring to Table 18-2,what is the numerical value of the upper control limit for the p chart?
A)0.92 
B)0.89 
C)0.71 
D)0.62

Quizplus · Accepted Answer

The upper control limit (UCL) for a p-chart is calculated using the formula UCL = p̄ + z√(p̄(1-p̄)/n), where p̄ is the average proportion defective, z is the z-value for the desired confidence level (usually 3 for 99.73% confidence), and n is the sample size. Without the specific values from Table 18-2, we assume the correct answer is based on typical calculations, which often result in values like 0.71.

TABLE 18-2 A Political Pollster Randomly Selects a Sample of 100 Voters