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Finding the Fourth Proportional to 485.10, 669.84 and 387.30

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Solution

The fourth proportional to 485.10, 669.84 and 387.30 is: 534.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.10 : 669.84 = 387.30 : x
  2. Step 2: Convert to fraction form
    485.10/669.84 = 387.30/x
  3. Step 3: Cross multiply
    485.10x = 669.84 × 387.30
  4. Step 4: Simplify right side
    485.10x = 259,429.03
  5. Step 5: Solve for x
    x = 259,429.03/485.10
  6. Step 6: Final answer
    x = 534.79

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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.