TABLE 17-2
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 17-2, 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 17-2
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 17-2, 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 typically calculated using the formula: UCL = p̄ + z * sqrt((p̄(1-p̄)/n)), where p̄ is the average proportion defective, z is the z-value for the desired confidence level (often 3 for 99.73% confidence), and n is the sample size. Without specific values from Table 17-2, the choice C (0.71) is assumed to be the correct UCL based on typical calculations.

TABLE 17-2 A Political Pollster Randomly Selects a Sample of 100 Voters