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Finding the Fourth Proportional to 456.63, 630.78 and 309.90

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Solution

The fourth proportional to 456.63, 630.78 and 309.90 is: 428.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    456.63 : 630.78 = 309.90 : x
  2. Step 2: Convert to fraction form
    456.63/630.78 = 309.90/x
  3. Step 3: Cross multiply
    456.63x = 630.78 × 309.90
  4. Step 4: Simplify right side
    456.63x = 195,478.72
  5. Step 5: Solve for x
    x = 195,478.72/456.63
  6. Step 6: Final answer
    x = 428.09

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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.