What is the 90% confidence intervalfor the varianceof the exam scores for 28 algebra students, if the standard deviationon their last exam was 12.7?
a. 122.8 < o < 316.5
b. 108.6 < o < 269.6
c. 10.4 < o < 16.4
d. 123.7 < o < 312.7
This solution provides calculations for 90% confidence interval.
