Question

The objective of this is to carry out a hypothesis test using the Welch Approximate t Procedure, to determine if there is evidence of a difference in the caffeine content between sugar and diet soda.

Use both Diet & Sugar Soda Data to answer questions

A) Use the Data Analysis ToolPak to carry out the Welch Approximate t Procedure. Include the output from Excel as a figure :

B) Identify the value of the test statistic from the Excel output :

C) Identify the p-value using the Excel output, and use it to determine whether or not the null hypothesis is rejected, assuming a 5% level of significance :

D) Calculate a 95% confidence interval for M1 - M2. Clearly state the point estimate for M1 - M2, the confidence coefficient, and the final confidence interval. To help with your calculations, use the rounded degrees of freedom that are reported as part of the Excel output. :

E) Provide an appropriate interpretation of the confidence interval you created. Does this interval support the results of your hypothesis test? Explain why or why not.

F) State the assumptions that must be satisfied for the inference procedures you just carried out to be valid. Using the plots you created as well as information provided in the question, is there reason to believe these assumptions have been violated? Justify your response

G) State a final conclusion about the caffeine content in sugar versus diet soda, using the results of this analysis :

Sugar	Diet
28.43	29.24
29.38	29.32
29.93	30.83
30.56	31.18
30.64	31.78
32.04	31.78
32.3	31.86
32.56	31.87
32.61	32.05
32.73	32.08
32.98	32.12
33.04	32.24
33.23	32.79
33.24	32.83
33.41	32.97
33.44	32.98
33.46	33.11
33.55	33.11
33.57	33.44
33.79	33.57
34	33.69
34.01	33.85
34.09	34.02
34.15	34.27
34.26	34.54
34.26	34.83
34.27	34.87
34.3	35.03
34.36	35.39
34.38	35.53
34.46	35.54
34.59	35.54
34.61	35.64
34.85	35.69
34.88	36.1
35.01	36.1
35.08	36.51
35.34	36.85
35.4	36.92
35.59	37.19
35.66	37.49
35.68	37.6
35.74	38.06
35.81	38.27
35.88	38.32
35.91	38.56
36.14	38.57
36.19	39.07
36.22	39.09
36.31	39.13
36.32	39.34
36.32	39.39
36.43	39.59
36.54	39.71
36.62	39.82
36.63	39.85
36.79	39.87
36.8	40.07
36.81	40.1
37.03	40.11
37.1	40.25
37.21	41.06
37.44	41.07
37.49	41.27
37.82	41.27
37.85	41.5
37.94	42.05
37.97	42.55
38.43	43.8
38.47	43.93
38.6	44.21
38.72	44.35
38.75	44.39
38.81	44.5
38.82	44.6
38.88	44.71
38.9	44.76
39.01	45.18
39.01	45.19
39.06	45.66
39.13	45.77
39.3	45.91
39.32	46
39.5	46.21
39.66	46.37
39.8	46.55
39.93	46.65
40	46.73
40.04	46.85
40.06	46.85
40.35	46.99
40.37	47.26
40.38	47.26
40.45	47.47
40.47	47.49
40.9	47.52
41.05	47.77
41.19	47.79
41.24	47.87
41.36	47.91
41.4	47.95
41.92	48.06
42.09	48.11
42.16	48.25
42.18	48.27
42.28	48.35
42.48	48.47
42.86	48.7
43.25	48.97
43.52	48.98
43.78	49.12
43.86	49.31
44	49.37
45.16	49.64
45.17	49.65
45.96	49.71
46.42	50.74
47.32	50.82
47.7	51.2
48.12	52.54

Answer 1

We can do it in Excel by steps:

Go to data Tab -> Data Analysis -> two sample test with unequal variances