Answer:
Median income has not changed
Mean income has increased
Step-by-step explanation:
Initial number of houses = 6
Earning per household = $40,000
The initial mean :
$(40,000 * 6) / 6 = $40000
Initial median :
40000, 40000, 40000, 40000, 40000, 40000
= 1/2(n+1)th term,
Median = 40000
A 7th household earns 4,000,000
Mean = ((40000*6) + 4,000,000) / 7 = $605,714
Median = 1/2(n+1)th term
40000, 40000, 40000, 40000, 40000, 40000, 4000000
Median = 4th term = 40000
, 
.