The median US salary is $50,700, according to US Census data. Using a one-sample t-test, test to see if participant income (INC1) is different from the national average. Use a two-tailed test and an alpha level of 5%.

1. Participant income is significantly greater than the national average
2. Participant income is significantly less than the national average
3. Participant income is not significantly different from the national average
4. Participant income cannot be compared to the national average

One-Sample Statistics

INCOME N=400 Mean=$47,112.92 Std. Deviation=$40,477.089 Std. Error Mean=$2,023.854

One-Sample Test

Test Value = 0

INCOME t=23.279 df=399 Sig. (2-tailed)=.000 Mean Difference=$47,112.920

95% Confidence Interval of the Difference

(lower)$43,134.17 (higher)$51,091.67