Question

How much time do you spend talking on your phone per day? I would like you to guess the number of minutes. This is your null hypothesis. I then want you to secure the data from your phone for the past month and conduct a one sample hypothesis test of the mean length of your phone calls per day. Be sure to show all your work by using excel and include your data set. Use a significance level of 0.05. You will have approximately 30 data values showing the total of minutes you spend per day. (Look at last month’s total and divide by the number of days.) Your phone bill will provide this information.

Answer 1

Let my talking time is 30 minutes in a day. so this is our null hypothesis. Now let us check the phone record of 30 days. I got the following values in minutes and entered in excel and use to to perform t test of mean, whose statistics is given by

	Tiime	Total time	(Time-mean(time))^2
1	22	22	104.7211
2	28	50	17.92111
3	22	72	104.7211
4	17	89	232.0544
5	18	107	202.5878
6	49	156	281.1211
7	42	198	95.38778
8	32	230	0.054444
9	28	258	17.92111
10	47	305	218.0544
11	40	345	60.32111
12	45	390	162.9878
13	41	431	76.85444
14	35	466	7.654444
15	30	496	4.987778
16	25	521	52.32111
17	38	559	33.25444
18	41	600	76.85444
19	26	626	38.85444
20	26	652	38.85444
21	18	670	202.5878
22	23	693	85.25444
23	33	726	0.587778
24	34	760	3.121111
25	47	807	218.0544
26	36	843	14.18778
27	31	874	1.521111
28	33	907	0.587778
29	21	928	126.1878
30	39	967	45.78778
Total	967		2525.367
Mean	32.23333		87.08161
t=	0.243418

As at 5% level of significance critical value of t at 29 df is 2.05 and as our t value is 0.243418 which is less that critical value so we can not reject our null hypothesis.