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Finding the Fourth Proportional to 280.71, 420.34 and 256.23

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Solution

The fourth proportional to 280.71, 420.34 and 256.23 is: 383.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.71 : 420.34 = 256.23 : x
  2. Step 2: Convert to fraction form
    280.71/420.34 = 256.23/x
  3. Step 3: Cross multiply
    280.71x = 420.34 × 256.23
  4. Step 4: Simplify right side
    280.71x = 107,700.98
  5. Step 5: Solve for x
    x = 107,700.98/280.71
  6. Step 6: Final answer
    x = 383.68

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.