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Finding the Fourth Proportional to 419.20, 628.35 and 256.99

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Solution

The fourth proportional to 419.20, 628.35 and 256.99 is: 385.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.20 : 628.35 = 256.99 : x
  2. Step 2: Convert to fraction form
    419.20/628.35 = 256.99/x
  3. Step 3: Cross multiply
    419.20x = 628.35 × 256.99
  4. Step 4: Simplify right side
    419.20x = 161,479.67
  5. Step 5: Solve for x
    x = 161,479.67/419.20
  6. Step 6: Final answer
    x = 385.21

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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.