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Finding the Fourth Proportional to 387.66, 534.78 and 256.71

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Solution

The fourth proportional to 387.66, 534.78 and 256.71 is: 354.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.66 : 534.78 = 256.71 : x
  2. Step 2: Convert to fraction form
    387.66/534.78 = 256.71/x
  3. Step 3: Cross multiply
    387.66x = 534.78 × 256.71
  4. Step 4: Simplify right side
    387.66x = 137,283.37
  5. Step 5: Solve for x
    x = 137,283.37/387.66
  6. Step 6: Final answer
    x = 354.13

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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.