Nipissing University has collected data from a sample 186 members of our alumni. The data include salary of Marketing, HR and Accounting graduates based on years of experience upon graduation from the School of Business.

Estimate the mean salary of HR students with 95% confidence (10%)

I have worked this through in excel using data analysis and XLSTAT and need assistance in understanding if I have reached the correct confidence interval. This question was posed to other Course Hero experts previously but I think they may not have been advised that it was a sample and the population standard deviation was not known. My results relied on the t-interval rather than the z-interval.

XLSTAT Data Analysis for Excel Statistic Human Resources Salary Human Resources Salary Nbr. of observations 186 Nbr. of missing values 0 Mean 44508.4 Obs. without missing data 186 Standard Error 784.97 Sum of weights 186 Median 43824 Minimum 16024.000 Mode 56824 Maximum 69024.000 Standard Deviation 10705.6 Freq. of minimum Sample Variance 1.1E+08 Freq. of maximum 1 Kurtosis -0.21764 Range 53000.000 Skewness -0.10452 1st Quartile 37824.000 Range 53000 Median 43824.000 Minimum 16024 3rd Quartile 52574.000 Maximum 69024 Sum 8278564.000 Sum 8278564 Mean 44508.409 Count 186 Variance (n) 113993036.478 Confidence Level(95.0%) 1548.64 Variance (n-1) 114609215.054 Standard deviation (n) 10676.752 LCL 42959.76 Based on 44508.41 1548.64 Standard deviation (n-1) 10705.569 UCL 46057.05 Based on 44508.41 + 1548.64 Variation coefficient (n) 0.240 Variation coefficient (n-1) 0.241 Interepration Skewness (Pearson) -0.104 Skewness (Fisher) -0.105 There is a 95% chance that the confidence interval from Skewness (Bowley) 0.186 42959.76 to 46057.05 contains the population mean Kurtosis (Pearson) -0.244 Kurtosis (Fisher) -0.218 Standard error of the mean 784.970 Lower bound on mean (95%) 42959.764 Upper bound on mean (95%) 46057.053