On 2 January 2017, White-Stone Ltd. commenced a mining operation. White-Stone Ltd. is required by the terms of provincial legislation to remediate the mine site when mining is completed, likely in 8 years time. This means that a provision for decommissioning must be recorded. White-Stone Ltd. estimates that decommissioning will cost $610,000 in 8 years. A reasonable market interest rate is 5%. White-Stone Ltd.'s year end is on December 31.

Required: a) Calculate the present value of the decommissioning obligation on January 2, 2017. b) Prepare a table that shows the balance of the obligation for three years (only).

Year	Opening Net Liability	Interest Expense Market Rate	Closing Net Liability
2017	a.	b.	c.
2018	d.	e.	f.
2019	g.	h.	i.

c) Assume that at the end of 2019, White-Stone Ltd. estimates that the cost of remediation will be $708,500, and that interest rates are now in the range of 7%. Calculate the interest expense for 2019, the new present value, and the adjustment to the obligation for the change in estimates.

Table 1-1: Present Value of 1: (P/F,i,n)
Period	3%	4%	5%	6%	7%	8%
1	0.97087	0.96154	0.95238	0.94340	0.93458	0.92593
2	0.94260	0.92456	0.90703	0.89000	0.87344	0.85734
3	0.91514	0.88900	0.86384	0.83962	0.81630	0.79383
4	0.88849	0.85480	0.82270	0.79209	0.76290	0.73503
5	0.86261	0.82193	0.78353	0.74726	0.71299	0.68058
6	0.83748	0.79031	0.74622	0.70496	0.66634	0.63017
7	0.81309	0.75992	0.71068	0.66506	0.62275	0.58349
8	0.78941	0.73069	0.67684	0.62741	0.58201	0.54027
9	0.76642	0.70259	0.64461	0.59190	0.54393	0.50025
10	0.74409	0.67556	0.61391	0.55839	0.50835	0.46319
11	0.72242	0.64958	0.58468	0.52679	0.47509	0.42888
12	0.70138	0.62460	0.55684	0.49697	0.44401	0.39711
Table 1-2: Present Value of an ordinary annuity of n payments of 1: (P/F,i,n)
Period	3%	4%	5%	6%	7%	8%
1	0.97087	0.96154	0.95238	0.94340	0.93458	0.92593
2	1.91347	1.88609	1.85941	1.83339	1.80802	1.78326
3	2.82861	2.77509	2.72325	2.67301	2.62432	2.57710
4	3.71710	3.62990	3.54595	3.46511	3.38721	3.31213
5	4.57971	4.45182	4.32948	4.21236	4.10020	3.99271
6	5.41719	5.24214	5.07569	4.91732	4.76654	4.62288
7	6.23028	6.00205	5.78637	5.58238	5.38929	5.20637
8	7.01969	6.73274	6.46321	6.20979	5.97130	5.74664
9	7.78611	7.43533	7.10782	6.80169	6.51523	6.24689
10	8.53020	8.11090	7.72173	7.36009	7.02358	6.71008
11	9.25262	8.76048	8.30641	7.88687	7.49867	7.13896
12	9.95400	9.38507	8.86325	8.38384	7.94269	7.53608