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Finding the Fourth Proportional to 387.81, 534.98 and 256.77

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Solution

The fourth proportional to 387.81, 534.98 and 256.77 is: 354.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.81 : 534.98 = 256.77 : x
  2. Step 2: Convert to fraction form
    387.81/534.98 = 256.77/x
  3. Step 3: Cross multiply
    387.81x = 534.98 × 256.77
  4. Step 4: Simplify right side
    387.81x = 137,365.53
  5. Step 5: Solve for x
    x = 137,365.53/387.81
  6. Step 6: Final answer
    x = 354.21

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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.