Final answer:
To calculate the percentage of classmates who own an iPhone, we consider 26% who own at least one device, subtract the 8% who own only an iPad, and add the 12% who own both an iPad and an iPhone. The result is that 30% of classmates own an iPhone.
Step-by-step explanation:
To solve this problem, we need to apply the principles of set theory and use the given percentages to find out the percentage of classmates who own an iPhone. Let's define the following terms:
- iPad ownership is 20%.
- iPad and iPhone ownership (intersection of both) is 12%.
- Neither ownership is 74%.
We start by acknowledging that the total percentage must add up to 100%. Since 74% do not own either device, we are left with 26% who own at least one of the devices (iPad, iPhone or both).
However, we know that 20% own an iPad, which includes those who own both an iPad and an iPhone. To avoid double-counting, we must subtract the 12% who own both from the total iPad ownership to find out how many own only an iPad. This calculation reveals that 8% (20% - 12%) own just an iPad.
Now, we can calculate the percentage of iPhone ownership. This includes individuals who own an iPhone with or without an iPad. To find the exclusive iPhone owners, we take the 26% who own either device and subtract the 8% who own only an iPad. This gives us 18% who own an iPhone.
The full calculation for iPhone ownership is therefore:
- iPhone only ownership: 26% (at least one device) - 8% (only an iPad) = 18%
- Total iPhone ownership (including those who also own an iPad): 18% + 12% (who own both) = 30%
Thus, the percentage of classmates who own an iPhone is 30%.