Exhibit 20.2.A trading magazine wants to determine the number of hours stock brokers work each week.In particular,the trading magazine wants to determine if the median numbers worked per week differs from 100 hours.The magazine samples 18 traders.For the Wilcoxon Signed-Rank Test,the value of the test statistic is . Refer to Exhibit 20.2.If T is assumed to follow a normal distribution,the value of the test statistic is:
A)153
B)2.94
C)0.128
D)-2.94

Question

Exhibit 20.2.A trading magazine wants to determine the number of hours stock brokers work each week.In particular,the trading magazine wants to determine if the median numbers worked per week differs from 100 hours.The magazine samples 18 traders.For the Wilcoxon Signed-Rank Test,the value of the test statistic is  . Refer to Exhibit 20.2.If T is assumed to follow a normal distribution,the value of the test statistic is:
A)153 
B)2.94 
C)0.128 
D)-2.94

Quizplus · Accepted Answer

For the Wilcoxon Signed-Rank Test, the test statistic is not assumed to follow a normal distribution. However, if the sample size is sufficiently large (i.e. n≥20), the distribution of the test statistic can be approximated by a normal distribution. Since n=18 in this case, the distribution of the test statistic cannot be approximated by a normal distribution. Therefore, the correct answer is B, which implies that there is not enough information to determine the value of the test statistic if it is assumed to follow a normal distribution.