17.2 miles
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In the given question, Amanda ran 32.8 miles more than Heather, and Amanda ran 50 miles.
To find out how many miles Heather ran (H), we need to subtract 32.8 miles from Amanda's distance (A):
- H = A - 32.8
- H = 50 - 32.8
- H = 17.2
Therefore, Heather ran 17.2 miles.