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Finding the Fourth Proportional to 419.15, 628.43 and 256.66

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Solution

The fourth proportional to 419.15, 628.43 and 256.66 is: 384.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.15 : 628.43 = 256.66 : x
  2. Step 2: Convert to fraction form
    419.15/628.43 = 256.66/x
  3. Step 3: Cross multiply
    419.15x = 628.43 × 256.66
  4. Step 4: Simplify right side
    419.15x = 161,289.99
  5. Step 5: Solve for x
    x = 161,289.99/419.15
  6. Step 6: Final answer
    x = 384.80

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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.