Question # Is there a relationship between Facebook use and age among college students? The following two-way table displays data for the 219 students who respon

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ANSWERED Is there a relationship between Facebook use and age among college students? The following two-way table displays data for the 219 students who responded to the survey. $$\begin{array}{ccc} & \text{Age} \\ \text{Facebook user?} & {\begin{array}{l|c|c|c} & \begin{array}{c} \text { Younger } \\ (18-22) \end{array} & \begin{array}{c} \text { Middle } \\ (23-27) \end{array} & \begin{array}{c} \text { Older } \\ (28 \text { and up)} \end{array} \\ \hline \text { Yes } & 78 & 49 & 21 \\ \hline \text { No } & 4 & 21 & 46 \end{array}} \\ \end{array}$$

What percent of the students who responded were older Facebook users? 2021-07-03

Let us first determine the row/column totals of the given table, which is the sum of all counts in the row/column: $$\begin{array}{c|c} \text{ Yonger } & \text{ Middle} & \text{ Older } & \text{ Row } & \text{ total} \\ \hline Yes& 78 &49& 21& 78+49+21=148 \\ \hline No &4 &21& 46 & 4+21+46=71 \\ \hline \text{ Column total }& 78+4=82& 49+21=70 &21+46=67& 148+71=219 \end{array}$$

We the note that the table contains 219 students in total (which is given in the bottom right corner of the above table), while 21 of the 219 students are older and Facebook users (which is given in the row ”Yes” and in the column *Older” of the above table).

$$\frac{21}{219}=\frac{7}{73} \sim 0.09589=9.589\%$$

Thus 9.589% of the students who responded were older Facebook users. 2021-08-04
One hundred adults and children were randomly selected and asked whether they spoke more than one language fluently. The data were recorded in a two-way table. Maria and Brennan each used the data to make the tables of joint relative frequencies shown below, but their results are slightly different. The difference is shaded. Can you tell by looking at the tables which of them made an error? Explain.
Younger Middle Older Row total
Yes 78 49 21 78+49+21=148
No 4 21 46 4+21+46=71
Column total 78+4=82 49+21=70 21+46=67 148+71=219
We the note that the table contains 219 students in total (which is given in the bottom right corner of the above table), while 82 of the 219 students are younger (which is given in the row &rdquo;Column total&rdquo; and in the column
Younger&rdquo; of the above table).
82/219 ~ 0.3744=37.44%
Thus 37.44% of the students who responded were younger. 2021-08-04

Let us first determine the row/column totals of the given table, which is the sum of all counts in the row/column:
Yonger Middle Older Row total
Yes 78 49 21 78+49+21=148
No 4 21 46 4+21+46=71
Column total 78+4=82 49+21=70 21+46=67 148+71=219
We the note that the table contains 219 students in total (which is given in the bottom right corner of the above table), while 21 of the 219 students are older and Facebook users (which is given in the row ”Yes” and in the column *Older” of the above table).
$$\displaystyle\frac{{67}}{{219}}\sim{0.3059}={30.59}\%$$
Thus 9.589% of the students who responded were older Facebook users.