Exercise 7.45 introduced a 2010 study about users of social networking sites such as Facebook. Table 7.32 shows the self-reported frequency of status updates on Facebook by age groups.

Table 7.32

(a) Based on the totals, if age and frequency of status updates are really unrelated, how many of the 156 users who are 18 to 22 years olds should we expect to update their status every day?
(b) Since there are 20 cells in this table, we€™ll save some time and tell you that the chi-square statistic for this table is 210.9. What should we conclude about a relationship (if any) between age and frequency of status updates?

Exercise 7.45

The Pew Research Center conducted a survey of randomly sampled American adults in 2008 and in 2010, asking them about their use of social networking sites such as Facebook. Table 7.31 shows age groups of social networking site users in 2008 and in 2010. Did the age distribution change significantly in the two-year time span? Show all details of the test.

Table 7.31

Transcribed Image Text:

18–22 23–35 36-49 50+ | Total ĮStatus/Age→ Every day 3-5 days/week 1-2 days/week Every few weeks Less often Total 59 47 69 65 47 33 23 30 35 136 117 161 25 32 23 21 156 47 34 169 99 170 74 314 364 234 243 947 2008 Total ȚAge/Year→ 2010 152 18–22 23-35 36–49 138 290 197 303 500 354 108 246 50+ Total 52 495 246 298 947 1442