Employ the confidence level and sample data to determine a confidence interval for determining the population (mean symbol).
Test scores: n = 98, x(bar over x) = 81.9, (standard deviation symbol) = 7.8; 99 percent
a. 79.9 < (mean symbol) < 83.9
b. 80.4 < (mean symbol)< 83.4
c. 80.6 < (mean symbol) < 83.2
d. 80.1 < (mean symbol) < 83.7