A random sample of 42 college graduates who worked during their program revealed that a student spent an average 5.5 years on the job before being promoted. The sample standard deviation was 1.1 years. Using the 0.99 degree of confidence, what is the confidence interval for the population mean?
5.04 and 5.96
5.06 and 5.94
2.67 and 8.33
4.40 and 6.60