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Finding the Fourth Proportional to 765.15, 1,056.14 and 485.29

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Solution

The fourth proportional to 765.15, 1,056.14 and 485.29 is: 669.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    765.15 : 1,056.14 = 485.29 : x
  2. Step 2: Convert to fraction form
    765.15/1,056.14 = 485.29/x
  3. Step 3: Cross multiply
    765.15x = 1,056.14 × 485.29
  4. Step 4: Simplify right side
    765.15x = 512,534.18
  5. Step 5: Solve for x
    x = 512,534.18/765.15
  6. Step 6: Final answer
    x = 669.85

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.