Answer :
The z value for a 93.8% confidence interval is approximately 1.87, which lies between the z values for 90% (1.645) and 95% (1.96) confidence intervals. This places 1.87 as the closest approximation given the options A. 1.54, B. 1.64, C. 1.87, and D. 1.96. Therefore, the correct option is C.
The z value for a 93.8% confidence interval estimation can be found using a z-table or calculator that provides critical values for normal distributions. This z value is the number of standard deviations you'd need to go from the mean of a standard normal distribution to capture the central 93.8% area underneath the curve.
Since we don't have a precise value for 93.8% in most z-tables, we approximate based on available values. A 90% confidence interval has a z value of approximately 1.645, and a 95% confidence interval has a z value of approximately 1.96. Looking at these, we need a value between 1.645 and 1.96 for a 93.8% confidence level. The closest value among the provided options that fall within this range is C. 1.87.
