Given:
Total members = 400
Percentage of members 17 and younger = 8%
Percentage of members aged 18 - 34 = 31%
Percentage of members aged 35 - 54 = 35%
Percentage of members aged 55 plus = 26%
To find the number of members between the ages of 18 and 34, use the formula below:
![\text{Number of members aged 18 and 34 = percentage aged 18 and 34 }\ast\text{ Total members}](https://img.qammunity.org/2023/formulas/mathematics/college/t9uhcmrm65a2xzertslyc6bvuplxbvyuiz.png)
Thus, we have:
![\text{Number ages 18 and 34 = }(31)/(100)\ast400=0.31\ast400=124](https://img.qammunity.org/2023/formulas/mathematics/college/mp173695btiz5801nlgy14je2ioyfjsii4.png)
Therefore, the number of health club members at this health club between the ages of 18 and 34 is 124
ANSWER: