Answer: a = 27%
Explanation:
From the given Venn diagram, the total number of players =
![11+3+7+5=26](https://img.qammunity.org/2020/formulas/mathematics/college/3a6jts6lc4onng1h4vdh5ojl57u9ugwiad.png)
The number of players preferred magazines books which are not coupon books = 7
The relative frequency for the players who preferred magazines books which are not coupon books (a)=
![\frac{\text{magazines books but not coupon books}}{\text{total players}}=(7)/(26)=0.269230769231](https://img.qammunity.org/2020/formulas/mathematics/college/98umxojn9h0aqc0favpzvuridoo9bkeoys.png)
In percent,
![0.269230769231* 100=26.9230769231\%\approx27\%](https://img.qammunity.org/2020/formulas/mathematics/college/gofemw2paviyl71jqibx7o08ieekxvmojo.png)
Hence, a = 27%