Someone hypothetically comes to you with some regression results that are confusing him:

Dependent Variable: Income in Thousands of Dollars
Independent Variable	Model 1	Model 2
Education (in years)	3.47***	3.47
Uses a computer at work (Y = 1,N = 0)	---	7.80
Constant	-20.45	-24.20
R-squared	.14	.14
n	1000	100

He is confused by what happens to the effect of education between Model 1 and Model 2: the value of the slope is the same, but it is no longer statistically significant.

What is the most likely explanation for this?

(Please explain in words. Calculations are not needed)