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Finding the Fourth Proportional to 456.66, 684.59 and 420.21

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Solution

The fourth proportional to 456.66, 684.59 and 420.21 is: 629.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    456.66 : 684.59 = 420.21 : x
  2. Step 2: Convert to fraction form
    456.66/684.59 = 420.21/x
  3. Step 3: Cross multiply
    456.66x = 684.59 × 420.21
  4. Step 4: Simplify right side
    456.66x = 287,669.46
  5. Step 5: Solve for x
    x = 287,669.46/456.66
  6. Step 6: Final answer
    x = 629.94

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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.