MS 150 Statistics quiz 05 • Name:
- __________ What is the probability that "our unguessable password" is p455w0rd?
 
- __________ What level of measurement is the password data?
 
- __________ If this was really the basis of a large scale study, what is the mode?
 
A convenience sample of 43 students in MS 150 Statistic fall 2007 yielded the following results:
| Psychoactive | Frequencies | 
| Substance | Never | About once a month | About once a week | 
A few times a week | Every day | 
| Betelnut without tobacco | 29 | 7 | 3 | 2 | 3 | 
| Betelnut with tobacco | 22 | 0 | 1 | 3 | 17 | 
- __________ Consider just the first data row, the data on those who chew without tobacco. What is the probability that a student does not chew betelnut?
 
- __________ Consider just the first data row, the data on those who chew without tobacco. For those who do chew, what is the mode?
 
- __________ Consider just the second data row, the data on those who chew with tobacco. For those who do chew, what is the mode?
 
- Considering the above two mode results, what impact does tobacco appear to have on betelnut chewing habits?
 
								
Bin upper limit for number of elements (x) | Frequency f	 | Rel freq, p(x) | x*p(x) | 
| 	5	 | 	5	 | 	0.04	 | 	0.18	 | 
| 	10	 | 	12	 | 	0.09	 | 	0.88	 | 
| 	15	 | 	30	 | 	0.22	 | 	3.31	 | 
| 	20	 | 	50	 | 	0.37	 | 	7.35	 | 
| 	25	 | 	25	 | 	0.18	 | 	4.60	 | 
| 	30	 | 	9	 | 	0.07	 | 	1.99	 | 
| 	35	 | 	5	 | 	0.04	 | 	1.29	 | 
| 	Sums:	 | 	136	 | 	1.00	 | 	19.60	 | 
	
The data in the table is adapted from a study done by Eelmine Järgmine on the number of elements found in a web page. A larger study by Google confirms this data. Although the data is technically not continuous data, use the table to report the mean number of different html elements found on a typical Internet web page.
							
- __________ What is the mean number of elements found on a typical web page?