A study of identity theft looked at how well consumers protect themselves from this increasingly prevalent crime. The behaviors of 62 college students were compared with the behaviors of 59 nonstudents. One of the questions was "When asked to create a password, I have used either my mother's maiden name, or my pet's name, or my birth date, or the last four digits of my social security number, or a series of consecutive numbers." For the students, 23 agreed with this statement while 28 of the nonstudents agreed.
(a) Display the data in a two-way table.
Students | Nonstudents | Total | |||
Agreed | 23 | 28 | 51 | ||
Disagreed | 39 | 31 | 70 | ||
Total | 62 | 59 | 121 |
Perform the chi-square test. (Round your χ^{2} to three decimal places and round your P-value to four decimal places.)
χ^{2} | = | 1.331 |
df | = | 1 |
P-value | = | .2486 |
(b) Reanalyze the data using the methods for comparing two proportions that we studied in the previous chapter. Compare the results and verify that the chi-square statistic is the square of the z statistic. (Test students who agreed minus nonstudents who agreed. Round your z to two decimal places and round your P-value to four decimal places.)
z=
P-value=
(c) The students in this study were junior and senior college students from two sections of a course in Internet marketing at a large northeastern university. The nonstudents were a group of individuals who were recruited to attend commercial focus groups on the West Coast conducted by a lifestyle marketing organization. Discuss how the method of selecting the subjects in this study relates to the conclusions that can be drawn from it.