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Finding the Fourth Proportional to 72.80, 108.80 and 65.60

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Solution

The fourth proportional to 72.80, 108.80 and 65.60 is: 98.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.80 : 108.80 = 65.60 : x
  2. Step 2: Convert to fraction form
    72.80/108.80 = 65.60/x
  3. Step 3: Cross multiply
    72.80x = 108.80 × 65.60
  4. Step 4: Simplify right side
    72.80x = 7,137.28
  5. Step 5: Solve for x
    x = 7,137.28/72.80
  6. Step 6: Final answer
    x = 98.04

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.