Question

6. Listed below are actual high temperatures and the high temperatures that were forecast five days earlier. Use a .05 significance level to test the claim of a zero mean difference between the actual high temperatures and the high temperatures that were forecast one day earlier. Use our 4-step procedure. This is a matched or paired samples hypothesis test. Actual high: 80 77 81 85 73 High forecast one day earlier: 78 75 81 85 76

Step 1: Ho____. Ha: ______

Step 2 : Significance level : 0.05

Step 3: test (Please state what test you used )

values for each required entry on calculator :__

P-value: __

Step 4: Decision:

Reason. Conclusion

Step 5: graph

Answer 1

Let d = Actual High - High Forecast

Following table shows the calculations:

Actual	Forecast	d	(d-mean)^2
80	78	2	3.24
77	75	2	3.24
81	81	0	0.04
85	85	0	0.04
73	76	-3	10.24
Total		1	16.8

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Step 3: test (Please state what test you used ): Paired t test

values for each required entry on calculator : VarStats of d, that is mean, sd and sample size

Using t test enter data

P-value: 0.838

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On TI enter data as follows:

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Now calculate VarStats

Following is the screen shot of t test:

Following is the graph: