Question

The global financial crisis (GFC) around 2008 had a significant
impact on the Australian economy and financial markets. We define the before
GFC period as Apr 2000 to July 2007, the GFC period as Aug 2007 to Dec 2009,
and the after-GFC period as after Jan 2010. Test the following hypotheses at 5%
significance. The Appendix provides the details for testing the difference in
means. a. The average AOret is the same before and after the GFC. b. The average AOSD is greater than the average AUDSD since April 2000

Date	AllOrd	Aoret	AOSD	AUDUSD	AUDSD	TV (m)	IR (%)	MV	PE
2000/4/28	3085.1		0.0703	0.5909	0.0253	5122.6	5.72	634878	22.08
2000/5/31	3040.6	-1.44%	0.0451	0.5735	0.0358	6373.5	5.98	616440	21.36
2000/6/30	3257.6	7.14%	0.0337	0.5986	0.0383	7439.0	6	661306	22.74
2000/7/31	3213.6	-1.35%	0.0181	0.5822	0.0318	6205.7	6	655211	22.4
2000/8/31	3261.7	1.50%	0.0211	0.5748	0.0392	6803.6	6.24	667249	19.92
2000/9/29	3246.1	-0.48%	0.0373	0.5433	0.0314	5353.3	6.25	665713	19.79
2000/10/31	3203.9	-1.30%	0.0354	0.5148	0.0409	6330.3	6.25	654696	19.34
2000/11/30	3222	0.56%	0.0273	0.5227	0.0410	6366.8	6.25	660245	19.1
2000/12/29	3154.7	-2.09%	0.0306	0.554	0.0379	5150.9	6.25	647981	18.76
2001/1/31	3291.5	4.34%	0.0341	0.5466	0.0496	6502.1	6.25	677262	19.64
2001/2/28	3274.1	-0.53%	0.0232	0.525	0.0311	6162.9	5.85	674838	19.13
2001/3/30	3096.9	-5.41%	0.0330	0.489	0.0400	7771.0	5.55	640182	17.97
2001/4/30	3270.3	5.60%	0.0295	0.5088	0.0471	6796.1	5.06	684694	19.06
2001/5/31	3317.2	1.43%	0.0216	0.51	0.0411	8380.9	5	706141	19.3
2001/6/29	3425.2	3.26%	0.0298	0.5075	0.0369	8988.5	5	731350	19.23
2001/7/31	3270.8	-4.51%	0.0311	0.5041	0.0291	8587.2	5	696368	18.25
2001/8/31	3217.8	-1.62%	0.0328	0.5342	0.0393	8630.8	5	690510	18.57
2001/9/28	2988	-7.14%	0.0755	0.4923	0.0485	8689.5	4.78	637779	17.48
2001/10/31	3185.3	6.60%	0.0438	0.5053	0.0437	8724.8	4.52	680742	18.61
2001/11/30	3276.9	2.88%	0.0297	0.52	0.0224	8851.4	4.5	701486	20.13
2001/12/31	3359.9	2.53%	0.0233	0.5106	0.0228	6793.5	4.28	720543	20.65
2002/1/31	3404	1.31%	0.0222	0.5078	0.0262	8554.5	4.25	730625	20.63
2002/2/28	3358.6	-1.33%	0.0218	0.5164	0.0186	9741.4	4.25	717582	21.62
2002/3/29	3363.3	0.14%	0.0287	0.5316	0.0190	8869.1	4.25	721098	22.32
2002/4/30	3299.5	-1.90%	0.0195	0.5397	0.0211	8457.3	4.25	716520	21.76
2002/5/31	3325.1	0.78%	0.0270	0.5674	0.0232	10220.3	4.45	723499	21.43
2002/6/28	3163.2	-4.87%	0.0262	0.5648	0.0359	9329.5	4.72	688364	20.36
2002/7/31	3032.6	-4.13%	0.0482	0.5478	0.0413	9753.9	4.75	664886	19.59
2002/8/30	3073.7	1.36%	0.0365	0.5532	0.0421	8769.3	4.75	674402	20.07
2002/9/30	2928.3	-4.73%	0.0378	0.5435	0.0232	9382.4	4.75	643353	19.03
2002/10/31	2995	2.28%	0.0356	0.5534	0.0162	9673.2	4.75	660222	19.15
2002/11/29	3025.2	1.01%	0.0372	0.5608	0.0215	9479.6	4.75	666129	18.67
2002/12/31	2975.5	-1.64%	0.0305	0.5662	0.0147	7434.2	4.75	655949	18.22
2003/1/31	2935.4	-1.35%	0.0274	0.5884	0.0265	9470.5	4.75	650167	18.03
2003/2/28	2778.4	-5.35%	0.0413	0.6054	0.0275	9827.0	4.75	614895	17.02
2003/3/31	2848.6	2.53%	0.0477	0.6036	0.0356	10661.4	4.75	627354	17.55
2003/4/30	2970.9	4.29%	0.0323	0.623	0.0220	9139.0	4.75	658441	18.71
2003/5/30	2979.8	0.30%	0.0222	0.6522	0.0373	11708.2	4.75	661936	18
2003/6/30	2999.7	0.67%	0.0239	0.6674	0.0279	12239.2	4.75	662017	18.14
2003/7/31	3106.7	3.57%	0.0229	0.6529	0.0422	12013.6	4.75	689132	18.89
2003/8/29	3202.9	3.10%	0.0143	0.64	0.0311	12283.1	4.75	707535	20.58
2003/9/30	3176.2	-0.83%	0.0220	0.6801	0.0381	13353.6	4.75	704703	19.29
2003/10/31	3282.4	3.34%	0.0220	0.7046	0.0216	13560.2	4.75	727806	19.67
2003/11/28	3195.7	-2.64%	0.0198	0.7206	0.0320	9831.6	4.98	711585	17.9
2003/12/31	3306	3.45%	0.0236	0.75	0.0200	9449.7	5.23	738376	18.5
2004/1/30	3283.6	-0.68%	0.0197	0.7644	0.0359	10338.6	5.25	738963	18.67
2004/2/27	3372.5	2.71%	0.0148	0.7708	0.0339	9687.3	5.25	759171	17.57
2004/3/31	3416.4	1.30%	0.0184	0.7589	0.0495	13633.8	5.25	787547	17.74
2004/4/30	3407.7	-0.25%	0.0195	0.722	0.0471	11224.0	5.25	786794	17.63
2004/5/31	3456.9	1.44%	0.0224	0.7143	0.0515	11365.3	5.25	799078	17.4
2004/6/30	3530.3	2.12%	0.0173	0.6889	0.0480	12675.5	5.25	816230	17.98
2004/7/30	3546.1	0.45%	0.0191	0.6986	0.0365	12176.1	5.25	820804	18.19
2004/8/31	3561.9	0.45%	0.0181	0.7011	0.0373	10235.5	5.25	823857	16.89
2004/9/30	3674.7	3.17%	0.0138	0.7147	0.0252	12411.8	5.25	853567	17.06
2004/10/29	3786.3	3.04%	0.0212	0.7461	0.0311	15263.1	5.25	880681	17.47
2004/11/30	3942.8	4.13%	0.0213	0.7775	0.0318	13496.9	5.25	917562	18.07
2004/12/31	4053.1	2.80%	0.0215	0.779	0.0344	9329.4	5.25	947527	19
2005/1/31	4106.7	1.32%	0.0167	0.7744	0.0320	9541.1	5.25	960387	19.52
2005/2/28	4156.5	1.21%	0.0195	0.7905	0.0251	12353.7	5.25	973627	19.84
2005/3/31	4100.6	-1.34%	0.0251	0.7719	0.0223	12866.1	5.49	966032	18.76
2005/4/29	3943.1	-3.84%	0.0352	0.7811	0.0215	11442.6	5.5	926651	18.66
2005/5/31	4070.4	3.23%	0.0291	0.7557	0.0222	11745.9	5.5	952202	17.3
2005/6/30	4229.9	3.92%	0.0213	0.7637	0.0207	13014.7	5.5	979544	17.93
2005/7/29	4346.7	2.76%	0.0207	0.7595	0.0272	11825.1	5.5	1006107	18.27
2005/8/31	4413.5	1.54%	0.0254	0.7471	0.0270	14393.2	5.5	1022227	18.18
2005/9/30	4592.6	4.06%	0.0255	0.7615	0.0258	14195.7	5.5	1010710	16.82
2005/10/31	4412.7	-3.92%	0.0462	0.7487	0.0196	12102.2	5.5	972768	16.02
2005/11/30	4583.6	3.87%	0.0247	0.7389	0.0187	12969.0	5.5	1010495	16.46
2005/12/30	4708.8	2.73%	0.0245	0.7337	0.0246	10778.2	5.5	1043449	16.95
2006/1/31	4880.2	3.64%	0.0304	0.751	0.0226	10994.2	5.5	1081953	17.55
2006/2/28	4878.4	-0.04%	0.0313	0.7382	0.0200	12798.8	5.5	1082109	17.29
2006/3/31	5087.2	4.28%	0.0270	0.7159	0.0310	15589.5	5.5	1152938	17.64
2006/4/28	5207	2.35%	0.0291	0.7542	0.0275	11212.5	5.5	1180979	18.03
2006/5/31	4972.3	-4.51%	0.0499	0.7636	0.0358	14682.3	5.73	1125117	15.8
2006/6/30	5034	1.24%	0.0569	0.7433	0.0356	14609.6	5.75	1143360	16.14
2006/7/31	4957.1	-1.53%	0.0403	0.7658	0.0215	11925.8	5.75	1126395	15.75
2006/8/31	5079.8	2.48%	0.0385	0.7627	0.0256	14780.6	5.99	1154573	16.16
2006/9/29	5113	0.65%	0.0354	0.748	0.0220	14749.8	6	1170607	15.24
2006/10/31	5352.9	4.69%	0.0292	0.7692	0.0169	16003.1	6	1222547	15.97
2006/11/30	5461.6	2.03%	0.0342	0.785	0.0165	16694.3	6.19	1254619	16.54
2006/12/29	5644.3	3.35%	0.0252	0.7913	0.0165	13513.2	6.25	1308120	17.36
2007/1/31	5757.7	2.01%	0.0337	0.772	0.0227	14355.8	6.25	1329638	17.92
2007/2/28	5816.5	1.02%	0.0346	0.788	0.0196	16635.1	6.25	1343901	17.28
2007/3/30	5978.8	2.79%	0.0477	0.807	0.0210	17611.3	6.25	1410777	16.34
2007/4/30	6158.3	3.00%	0.0338	0.8268	0.0256	14867.1	6.25	1452446	16.8
2007/5/31	6341.8	2.98%	0.0364	0.8244	0.0201	19887.7	6.25	1494763	17.08
2007/6/29	6310.6	-0.49%	0.0358	0.8487	0.0205	20028.3	6.25	1505801	15.98
2007/7/31	6187.5	-1.95%	0.0399	0.8572	0.0343	18857.3	6.25	1461694	15.86
2007/8/31	6248.3	0.98%	0.0912	0.8214	0.0708	22698.2	6.45	1466734	15.32
2007/9/28	6580.9	5.32%	0.0400	0.8827	0.0397	16730.1	6.5	1558061	15.77
2007/10/31	6779.1	3.01%	0.0415	0.9216	0.0409	24730.9	6.5	1602109	16.05
2007/11/30	6593.6	-2.74%	0.0586	0.8865	0.0590	18066.1	6.7	1554691	15.6
2007/12/31	6421	-2.62%	0.0473	0.8816	0.0351	25253.2	6.75	1511599	15.05
2008/1/31	5697	-11.28%	0.1173	0.8884	0.0387	20538.0	6.75	1341299	13.47
2008/2/29	5674.7	-0.39%	0.0726	0.9466	0.0278	26848.4	6.96	1331469	13.13
2008/3/31	5409.7	-4.67%	0.0870	0.918	0.0405	21280.3	7.22	1302711	12.79
2008/4/30	5657	4.57%	0.0576	0.9337	0.0281	19036.5	7.25	1364748	13.53
2008/5/30	5773.9	2.07%	0.0387	0.9559	0.0291	21162.7	7.25	1399502	14.02
2008/6/30	5332.9	-7.64%	0.0503	0.9626	0.0190	23464.8	7.25	1300700	13.11
2008/7/31	5052.6	-5.26%	0.0746	0.9434	0.0270	21413.1	7.25	1235582	12.05
2008/8/29	5215.5	3.22%	0.0569	0.8639	0.0442	19236.5	7.25	1276564	12.27
2008/9/30	4631.3	-11.20%	0.1035	0.7996	0.0932	24204.0	7.02	1138867	12.49
2008/10/31	3982.7	-14.00%	0.1738	0.668	0.1757	23306.6	6.18	980775	11.26
2008/11/28	3672.7	-7.78%	0.1401	0.6572	0.0884	20597.0	5.33	904561	10.26
2008/12/31	3659.3	-0.36%	0.0773	0.6928	0.0639	18291.7	4.35	925795	10.38
2009/1/30	3478.1	-4.95%	0.0818	0.6438	0.0746	16482.8	4.25	884973	9.78
2009/2/27	3296.9	-5.21%	0.0450	0.6454	0.0526	19078.2	3.35	845980	9.93
2009/3/31	3532.3	7.14%	0.0701	0.6873	0.0543	27390.7	3.25	920531	10.98
2009/4/30	3744.7	6.01%	0.0630	0.7265	0.0579	23797.7	3.06	979901	11.42
2009/5/29	3813.3	1.83%	0.0637	0.7912	0.0522	29423.5	3	1009215	11.98
2009/6/30	3947.8	3.53%	0.0637	0.8114	0.0680	33730.5	3	1060843	12.38
2009/7/31	4249.5	7.64%	0.0572	0.8281	0.0370	27502.9	3	1146263	13.27
2009/8/31	4484.1	5.52%	0.0518	0.8393	0.0481	41643.0	3	1215069	15.69
2009/9/30	4739.3	5.69%	0.0466	0.8801	0.0362	38015.2	3	1302126	15.84
2009/10/30	4646.9	-1.95%	0.0550	0.9161	0.0414	32609.5	3.21	1276306	15.68
2009/11/30	4715.5	1.48%	0.0574	0.9178	0.0377	27281.7	3.48	1296018	15.84
2009/12/31	4882.7	3.55%	0.0325	0.8969	0.0342	20693.0	3.74	1348135	16.38
2010/1/29	4596.9	-5.85%	0.0396	0.8909	0.0354	20352.1	3.75	1268074	15.93
2010/2/26	4651.1	1.18%	0.0494	0.8899	0.0335	24764.6	3.75	1282488	16.16
2010/3/31	4893.1	5.20%	0.0264	0.9159	0.0251	31064.0	3.98	1362651	15.82
2010/4/30	4833.9	-1.21%	0.0300	0.93	0.0256	26321.0	4.22	1348961	15.51
2010/5/31	4453.6	-7.87%	0.0761	0.849	0.0606	33693.3	4.48	1243814	14.56
2010/6/30	4324.8	-2.89%	0.0554	0.8523	0.0622	26221.4	4.5	1210725	14.21
2010/7/30	4507.4	4.22%	0.0471	0.8986	0.0464	22975.6	4.5	1262263	14.68
2010/8/31	4438.8	-1.52%	0.0451	0.8918	0.0302	28492.7	4.5	1239724	13.33
2010/9/30	4636.9	4.46%	0.0392	0.9667	0.0295	28430.5	4.5	1285574	14.34
2010/10/29	4733.4	2.08%	0.0369	0.9761	0.0350	26372.9	4.5	1311646	14.55
2010/11/30	4676.4	-1.20%	0.0308	0.9618	0.0335	27921.3	4.73	1293156	14.59
2010/12/31	4846.9	3.65%	0.0264	1.0163	0.0313	23924.4	4.75	1338295	15.22
2011/1/31	4849.9	0.06%	0.0267	0.9924	0.0294	20630.8	4.75	1339504	15.21
2011/2/28	4923.6	1.52%	0.0235	1.0163	0.0262	23958.8	4.75	1359159	15.28
2011/3/31	4928.6	0.10%	0.0442	1.0334	0.0296	35801.1	4.75	1365948	16.55
2011/4/29	4899	-0.60%	0.0339	1.09	0.0324	21972.5	4.75	1353872	16.17
2011/5/31	4788.9	-2.25%	0.0426	1.0709	0.0382	27379.7	4.75	1322448	15.32
2011/6/30	4659.8	-2.70%	0.0429	1.0739	0.0350	27622.4	4.75	1282323	14.83
2011/7/29	4500.5	-3.42%	0.0430	1.0954	0.0299	25657.5	4.75	1241004	14.41
2011/8/31	4369.8	-2.90%	0.0869	1.0691	0.0464	33150.6	4.75	1204539	13.39
2011/9/30	4070.1	-6.86%	0.0809	0.9781	0.0582	29189.3	4.75	1122754	12.23
2011/10/31	4360.5	7.13%	0.0736	1.0509	0.0619	22168.2	4.75	1203789	12.93
2011/11/30	4184.7	-4.03%	0.0564	1.0021	0.0446	23043.7	4.51	1150845	12.54
2011/12/30	4111	-1.76%	0.0579	1.0156	0.0427	19155.6	4.3	1110921	12.38
2012/1/31	4325.7	5.22%	0.0383	1.0637	0.0294	16052.3	4.25	1169315	13
2012/2/29	4388.1	1.44%	0.0352	1.0816	0.0252	23882.7	4.25	1185756	13.7
2012/3/30	4420	0.73%	0.0326	1.0402	0.0301	24981.3	4.25	1202787	14.07
2012/4/30	4467.2	1.07%	0.0253	1.0453	0.0247	17181.2	4.25	1212477	14.15
2012/5/31	4133.7	-7.47%	0.0520	0.9727	0.0364	24509.4	3.77	1124872	13.37
2012/6/29	4135.5	0.04%	0.0423	1.0191	0.0304	21229.1	3.54	1125319	13.42
2012/7/31	4289.4	3.72%	0.0387	1.0526	0.0260	18060.2	3.5	1169422	13.87
2012/8/31	4339	1.16%	0.0274	1.0301	0.0202	22386.1	3.5	1182824	14.64
2012/9/28	4406.3	1.55%	0.0229	1.0464	0.0277	21286.5	3.5	1201624	15.01
2012/10/31	4535.4	2.93%	0.0243	1.0378	0.0268	19731.7	3.27	1237237	15.43
2012/11/30	4518	-0.38%	0.0298	1.0431	0.0179	19740.1	3.25	1231184	15.56
2012/12/31	4664.6	3.24%	0.0177	1.0384	0.0110	15566.7	3.03	1273350	16.07
2013/1/31	4901	5.07%	0.0230	1.0394	0.0176	16767.3	3	1338122	16.87
2013/2/28	5120.4	4.48%	0.0365	1.0275	0.0234	20369.8	3	1398533	18.62
2013/3/29	4979.9	-2.74%	0.0394	1.0426	0.0205	20807.5	3	1368938	18
2013/4/30	5168.6	3.79%	0.0383	1.0368	0.0213	19351.6	3	1420498	18.66
2013/5/31	4914	-4.93%	0.0332	0.9649	0.0397	22394.6	2.8	1349414	17.72
2013/6/28	4775.4	-2.82%	0.0476	0.9275	0.0427	20255.1	2.75	1313446	17.26
2013/7/31	5035.7	5.45%	0.0447	0.9037	0.0395	19332.5	2.75	1385805	18.24
2013/8/30	5125.3	1.78%	0.0340	0.8947	0.0335	20183.7	2.55	1411134	18.6
2013/9/30	5217.7	1.80%	0.0286	0.9309	0.0273	19196.9	2.5	1439990	18.49
2013/10/31	5420.3	3.88%	0.0276	0.949	0.0219	18294.1	2.5	1496157	19.09
2013/11/29	5314.3	-1.96%	0.0249	0.9087	0.0256	16582.2	2.5	1465298	18.2
2013/12/31	5353.1	0.73%	0.0338	0.8948	0.0267	16033.6	2.5	1476840	17.55
2014/1/31	5205.1	-2.76%	0.0312	0.8763	0.0324	15605.2	2.5	1436306	17.07
2014/2/28	5415.4	4.04%	0.0300	0.8947	0.0289	19225.9	2.5	1495858	16.83
2014/3/31	5403	-0.23%	0.0280	0.9221	0.0273	20915.3	2.5	1509122	16.97
2014/4/30	5470.8	1.25%	0.0250	0.9287	0.0170	13911.1	2.5	1529689	17.18
2014/5/30	5473.8	0.05%	0.0249	0.9319	0.0154	16327.3	2.5	1523009	17.52
2014/6/30	5382	-1.68%	0.0279	0.942	0.0172	16897.1	2.5	1497850	17.29
2014/7/31	5623.1	4.48%	0.0229	0.9324	0.0155	16377.4	2.5	1563616	17.95
2014/8/29	5624.6	0.03%	0.0269	0.9349	0.0164	17104.4	2.5	1562546	17.14
2014/9/30	5296.8	-5.83%	0.0304	0.8752	0.0308	18276.4	2.5	1478396	14.69
2014/10/31	5505	3.93%	0.0361	0.8805	0.0328	19002.3	2.5	1536817	16.39
2014/11/28	5298.1	-3.76%	0.0298	0.8491	0.0368	15414.8	2.5	1481191	15.35
2014/12/31	5388.6	1.71%	0.0517	0.8202	0.0268	17856.2	2.5	1509820	15.8
2015/1/30	5551.6	3.02%	0.0356	0.7781	0.0411	15127.6	2.5	1555839	16.28
2015/2/27	5898.5	6.25%	0.0343	0.7792	0.0436	18518.2	2.28	1653829	17.93
2015/3/31	5861.9	-0.62%	0.0354	0.7634	0.0371	19791.1	2.25	1666895	18.18
2015/4/30	5773.7	-1.50%	0.0346	0.7981	0.0385	14718.9	2.25	1644238	17.96
2015/5/29	5774.9	0.02%	0.0367	0.7663	0.0371	16723.2	2.04	1648922	17.73
2015/6/30	5451.2	-5.61%	0.0468	0.768	0.0265	17590.5	2	1553918	16.84
2015/7/31	5681.7	4.23%	0.0472	0.7294	0.0329	16531.3	2	1624000	17.53
2015/8/31	5222.1	-8.09%	0.0662	0.7149	0.0297	18806.2	2	1496640	16.36
2015/9/30	5058.6	-3.13%	0.0727	0.701	0.0348	19898.9	2	1458501	16.62
2015/10/30	5288.6	4.55%	0.0407	0.7099	0.0358	16891.5	2	1530502	17.38
2015/11/30	5218.2	-1.33%	0.0459	0.7189	0.0266	18014.9	2	1514585	17
2015/12/31	5344.6	2.42%	0.0476	0.7306	0.0277	16912.3	2	1556340	17.38
2016/1/29	5056.6	-5.39%	0.0478	0.71	0.0350	14665.5	2	1472464	16.49
2016/2/29	4947.9	-2.15%	0.0604	0.714	0.0405	21260.5	2	1440028	16.22
2016/3/31	5151.8	4.12%	0.0407	0.7657	0.0415	21037.5	2	1512556	17.43
2016/4/29	5316	3.19%	0.0369	0.7655	0.0314	15683.6	2	1562011	17.99
2016/5/31	5447.8	2.48%	0.0343	0.7242	0.0331	18535.7	1.77	1600523	19.88
2016/6/30	5310.4	-2.52%	0.0502	0.7426	0.0318	18475.4	1.75	1561321	19.4
2016/7/29	5644	6.28%	0.0282	0.7522	0.0255	15675.5	1.75	1661467	20.63
2016/8/31	5529.4	-2.03%	0.0249	0.7514	0.0268	17854.1	1.52	1622714	19.95
2016/9/30	5525.1	-0.08%	0.0355	0.763	0.0265	18354.4	1.5	1625068	19.72
2016/10/31	5402.4	-2.22%	0.0272	0.7613	0.0212	15668.4	1.5	1590262	19.34
2016/11/30	5502.4	1.85%	0.0481	0.7474	0.0323	19413.0	1.5	1621542	20.45
2016/12/30	5719.1	3.94%	0.0296	0.7236	0.0241	16335.0	1.5	1685399	21.24
2017/1/31	5675	-0.77%	0.0276	0.7567	0.0214	13953.8	1.5	1672837	21.11
2017/2/28	5761	1.52%	0.0197	0.7688	0.0150	17893.0	1.5	1698852	19.52
2017/3/31	5903.8	2.48%	0.0292	0.7644	0.0259	20731.3	1.5	1755295	19.89
2017/4/28	5947.6	0.74%	0.0186	0.7475	0.0190	15748.2	1.5	1769323	20.05
2017/5/31	5761.3	-3.13%	0.0252	0.745	0.0262	20384.5	1.5	1707562	18.32
2017/6/30	5764	0.05%	0.0394	0.7692	0.0206	19770.3	1.5	1708808	18.36
2017/7/31	5773.9	0.17%	0.0344	0.7987	0.0312	16985.1	1.5	1714070	18.35
2017/8/31	5776.3	0.04%	0.0247	0.7898	0.0255	20619.9	1.5	1717025	17.12
2017/9/29	5744.9	-0.54%	0.0169	0.7839	0.0277	16965.3	1.5	1711706	16.4
2017/10/31	5976.4	4.03%	0.0209	0.7673	0.0228	16724.2	1.5	1783772	16.93
2017/11/30	6057.2	1.35%	0.0197	0.7585	0.0172	17557.7	1.5	1807337	17.02
2017/12/29	6167.3	1.82%	0.0137	0.78	0.0223	15675.8	1.5	1844990	17.36
2018/1/31	6146.5	-0.34%	0.0177	0.8073	0.0186	16649.1	1.5	1839449	17.34
2018/2/28	6117.3	-0.48%	0.0444	0.7792	0.0271	17936.8	1.5	1833577	16.97
2018/3/29	5868.9	-4.06%	0.0324	0.7665	0.025	18653.4	1.5	1777041	16.3
2018/4/30	6071.6	3.45%	0.016	0.7570	0.0192	16695.2	1.5	1840001	16.87
2018/5/31	6123.5	0.85%	0.0184	0.7564	0.0254	20732.7	1.5	1855652	17.1
2018/6/30	6289.7	2.71%	0.0230	0.7391	0.0241	23759.5	1.5	1898099	17.6
2018/7/31	6366.2	1.22%	0.0243	0.7431	0.0230	15917.3	1.5	1921867	17.79

Answer 1

A)

average AOret before GFC= 0.845287 %

average AOret after GFC= 0.374412 %

Standard deviation (std dev) of AOret before GFC= 2.91 %

No of sample points before GFC = 87

standard error of the sample == .00291/ (87^0.5)= .00312

For 5 % significance level we will check whether these two averages are statistically different. To do that we will calculate 95 % confidence interval around before/after GFC mean.

Let us take before GFC average and calculate confidence interval. As we do not know population variance, we will use t- distribution to decide confidence interval

Lower bound= mean - (critical value from t table* standard error)= 0.00845287-(1.99*0.00312)=0.00224407

Upper bound= mean + (critical value from t table* standard error)= 0.00845287+(1.99*0.00312)=0.01466167   

the range for confidence interval at 95% confidence interval for before GFC is: 0.224407% - 1.466167%  

Average value of after GFC i.e. 0.374412 % lies between these critical values. Hence, we can conclude that the average AOret is the same before and after the GFC.

B)

Average AOSD during the period= 3.82%

Average AUDSD during the period= 3.29%

We will calculate one tail 95% confidence interval for AUDSD to confirm whether average AOSD is greater than average AUDSD.

Standard deviation (std dev) of AOSD = 0.015848

No of sample points before GFC = 220

standard error of the sample == 0.015848/ (220^0.5)= 0.001068

Upper bound= mean + (critical value from t table* standard error)= 0.0329+(1.664*0.001068)=0..034677152

At 95% confidence level we can prove that average AOSD is greater than average AUDSD, which indirectly means that these values are statistically significant from each other and average AOSD is greater than average AUDSD.