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Finding the Fourth Proportional to 387.30, 534.90 and 256.86

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Solution

The fourth proportional to 387.30, 534.90 and 256.86 is: 354.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.30 : 534.90 = 256.86 : x
  2. Step 2: Convert to fraction form
    387.30/534.90 = 256.86/x
  3. Step 3: Cross multiply
    387.30x = 534.90 × 256.86
  4. Step 4: Simplify right side
    387.30x = 137,394.41
  5. Step 5: Solve for x
    x = 137,394.41/387.30
  6. Step 6: Final answer
    x = 354.75

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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.