T-tests are only used for two sample groups, either on a pre post-test basis or between two samples (independent or dependent). The t-test is optimized to deal with small sample numbers which is often the case with managers in any business.
When samples are excessively large the t test becomes difficult to manage due to the mathematical calculations involved.
Calculate the t value for independent groups . Check the accuracy of your calculations. Using the raw measurement data presented above, determine whether or not there exists a statistically significant difference between the salaries of female and male human resource managers using the appropriate t-test. Develop a research question, testable hypothesis, confidence level, and degrees of freedom. Draw the appropriate conclusions with respect to female and male HR salary levels. Report the required t critical values based on the degrees of freedom 

Salary Level
Female HR Directors
Male HR Directors
*Do not forget what we all learned in high school about 0s