Study the following table, which shows the number of units of a product manufactured and sold by a company in five years, and answer questions
| Years |
Number of units (in thousands) Manufactured |
Sold |
| 2013 | 350 | 320 |
| 2014 | 375 | 315 |
| 2015 | 300 | 280 |
| 2016 | 450 | 423 |
| 2017 | 420 | 360 |
The ratio of the total number of units sold in 2014 and 2015 to the number of units manufactured in 2017 is:
1
17 : 12
2
19 : 14
3
9 : 8
4
14 : 17