Answer :
The z value for a 93.8% confidence interval is not one of the standard values usually memorized, but it falls between the z-value for a 90% confidence interval (1.645) and for a 95% confidence interval (1.96). Option (c) 1.87 is the best choice among the options provided.
The question is about determining the z value for a 93.8% confidence interval. The critical value (z-score) for a confidence interval is the number of standard deviations you need to go from the mean of the normal distribution to capture the central percentage of the distribution. For a 93.8% confidence interval, we don't have a commonly memorized value, but generally the z-score for a 90% confidence interval is 1.645, and for a 95% confidence interval it is 1.96. The z-value for a 93.8% confidence interval would fall between those two values.
Given the options, (c) 1.87 is the closest to the actual value for a 93.8% confidence interval, which does indeed fall between 1.645 and 1.96.
