Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Locks & Dam | Location [L ] | River Mile | Lock Side | Lock Lift/Drop (in feet) | Pool Length (miles) |
| --- | --- | --- | --- | --- | --- |
| Emsworth Locks and Dam | Pittsburgh, Pennsylvania | 6.2 | RDB | 18 | 6.2+ |
| Dashields Locks and Dam | Coraopolis, Pennsylvania | 13.3 | LDB | 10 | 7.1 |
| Montgomery Locks and Dam | Monaca, Pennsylvania | 31.7 | LDB | 18 | 18.4 |
| New Cumberland Locks and Dam | Stratton, Ohio | 54.3 | RDB | 21 | 22.6 |
| Pike Island Locks and Dam | Wheeling, West Virginia | 84.2 | LDB | 21 | 29.9 |
| Hannibal Locks and Dam | Hannibal, Ohio | 126.4 | RDB | 21 | 42.2 |
| Willow Island Locks and Dam H | Newport, Ohio | 161.7 | RDB | 20 | 35.3 |
| Belleville Locks and Dam | Reedsville, Ohio | 203.9 | RDB | 22 | 42.2 |
| Racine Locks and Dam | Letart, West Virginia | 237.5 | LDB | 22 | 33.6 |
| Robert C. Byrd Locks and Dam | Gallipolis Ferry, West Virginia | 279.2 | LDB | 23 | 41.7 |
| Greenup Locks and Dam | Greenup, Kentucky | 341.0 | LDB | 30 | 61.8 |
| Captain Anthony Meldahl Locks and Dam | Foster, Kentucky | 436.2 | RDB | 30 | 95.2 |
| Markland Locks and Dam | Warsaw, Kentucky | 531.5 | LDB | 35 | 95.3 |
| McAlpine Locks and Dam | Louisville, Kentucky | 606.8 | LDB | 37 | 75.3 |
| Cannelton Locks and Dam H | Cannelton, Indiana | 720.7 | RDB | 25 | 113.9 |
| Newburgh Locks and Dam | Newburgh, Indiana | 776.1 | RDB | 16 | 55.4 |
| John T. Myers Locks and Dam | Mt. Vernon, Indiana | 846.0 | RDB | 18 | 69.9 |
| Smithland Locks and Dam H | Hamletsburg, Illinois | 918.5 | RDB | 22 | 72.5 |
| Locks and Dam Number 52 | Brookport, Illinois | 938.9 | RDB | 12 | 20.4 |
| Locks and Dam Number 53 | Grand Chain, Illinois | 962.0 | RDB | ≤17 | 23.7 |
| Olmsted Locks and Dam | Olmsted, Illinois | 964.4 | RDB | ≤30 | 46.0 |
Question:
What is the River Mile with a RDB lock side and a pool length of 55.4?
Answer:
776.1