Imagine that a researcher has conducted a survey to measure feelings of political efficacy in a developing country. The researcher has randomly selected 25 citizens and asked them to rate their feelings of political efficacy on a scale from -100 to 100. Assume that the true population distribution for this is normal with unknown mean and variance. If the sample mean is X = 16.8 and the sample standard deviation s = 40, construct a 95% confidence interval for the population mean.