Confidence Interval

Confidence interval is said to be range of values showing lower and upper bound, in which, for example, there is blank % likelihood that the family income in constant dollar amount is between upper and lower bound. It is a boundary of stated values that tend to show likelihood in which value of constraint lies with it (Wagner, 2016). When we increase the sample size, let’s say from 10% to 40%, we can see the width of the confidence interval changed or decreased. This is also because the normal measured error will likely decrease in value (Frankfort-Nachmias & Leon-Guerrero, 2015). Confidence interval is underutilized because if a social science research hypothesis proved insignificant difference between what is measured or proved specific case due to sample error, then the use of confidence interval maybe underutilized. It could be another way of saying if the upper and lower bound means there is a % family income in constant $ to fall between the two bound or % confident that the unknown population of interest lies within stated bound, then there is a margin or error or standard error of the mean.

Frankfort-Nachmias, C., & Leon-Guerrero, A. (2015). Social statistics for a diverse society (7th

            ed.). Thousand Oaks, CA: Sage Publications.

Wagner, W. E. (2016). Using IBM® SPSS® statistics for research methods and social science statistics (6th ed.). Thousand Oaks, CA: Sage Publications.