Index questions: Drop in farm population; hourly earnings in mining

1. The Bureau of the Census reported that the farm population dropped from 30.5 million in 1940 to 6.5 million in 1999. What is the index for 1999 based on 1940?

Choose the right answer below and if you can explain in one sentence:

a). 469.7
b). 100.0
c). 21.3
d). 78.7

2. If the average hourly earnings in mining in 1998 was $7.67 and for the most recent month it was $14.90, what is the index of hourly earnings for the most recent month based on 1998?

a). 100.0
b). 186.9
c). 151.5
d). 194.3