9 A random sample of adults in the UK were asked to state their primary source of news: television (T), internet (I), newspapers (N) or radio (R). The responses were classified by age group, and an analysis was carried out to see if there is any association between age group and primary source of news.
Fig. 9 is a screenshot showing part of the spreadsheet used to analyse the data. Some values in the spreadsheet have been deliberately omitted.
\begin{table}[h]
| A | B | C | D | E | F |
| 1 | Source | Age group | |
| 2 | of news | 18-32 | 33-47 | 48-64 | 65+ | |
| 3 | T | 63 | 61 | 71 | 80 | 275 |
| 4 | I | 33 | 33 | 22 | 12 | 100 |
| 5 | N | 9 | 8 | 11 | 20 | 48 |
| 6 | R | 4 | 9 | 9 | 5 | 27 |
| 7 | | 109 | 111 | 113 | 117 | 450 |
| 8 | | | | | | |
| 9 | | Expected frequencies | |
| 10 | | 66.61 | 67.83 | 69.06 | 71.50 | |
| 11 | | 24.22 | 24.67 | | 26.00 | |
| 12 | | 11.63 | 11.84 | 12.05 | 12.48 | |
| 13 | | 6.54 | 6.66 | 6.78 | 7.02 | |
| 14 | | | | | | |
| 15 | Contributions to the test statistic | |
| 16 | | 0.20 | 0.69 | 0.05 | 1.01 | |
| 17 | | 3.18 | 2.82 | | 7.54 | |
| 18 | | 0.59 | | 0.09 | 4.53 | |
| 19 | | 0.99 | 0.82 | 0.73 | 0.58 | |
| 20 | test statistic | 25.45 |
\captionsetup{labelformat=empty}
\caption{Fig. 9}
\end{table}
- (A) State the sample size.
(B) Give the name of the appropriate hypothesis test.
(C) State the null and alternative hypotheses. - Showing your calculations, find the missing values in cells
- D11,
- D17 and
- C18.
- Complete the appropriate hypothesis test at the \(5 \%\) level of significance.
- Discuss briefly what the data suggest about primary source of news. You should make a comment for each age group.