Marcia observed the following cash flow series (in $1000 units) in an accounting report at work. The actual amounts in years 1 and 4 are missing; however, the report states that the present worth in year 0 was $348,000 at an interest rate of 13% per year. Calculate the value of x.

Year	0	1	2	3	4	5	6
Cash flow, $1000	40	x	40	40	x	40	40

The value of x is determined to be $ .