Question

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

Answer 1

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 not significantly different from the national average

One-Sample Statistics

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

t Test for Hypothesis of the Mean
Data
Null Hypothesis                m=	50700
Level of Significance	0.05
Sample Size	400
Sample Mean	47112.92
Sample Standard Deviation	40477.089
Intermediate Calculations
Standard Error of the Mean	2023.8545
Degrees of Freedom	399
t Test Statistic	-1.7724
Two-Tail Test
Lower Critical Value	-1.9659
Upper Critical Value	1.9659
p-Value	0.0771
Do not reject the null hypothesis

Calculated t= -1.7724, P=0.0771 which is > 0.05 level of significance.

Ho is not rejected.

Participant income is not significantly different from the national average

95% CI for difference

lower limit	-7565.83071
Upper limit	391.6707062