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Finding the Fourth Proportional to 458.55, 686.63 and 420.49

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Solution

The fourth proportional to 458.55, 686.63 and 420.49 is: 629.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    458.55 : 686.63 = 420.49 : x
  2. Step 2: Convert to fraction form
    458.55/686.63 = 420.49/x
  3. Step 3: Cross multiply
    458.55x = 686.63 × 420.49
  4. Step 4: Simplify right side
    458.55x = 288,715.51
  5. Step 5: Solve for x
    x = 288,715.51/458.55
  6. Step 6: Final answer
    x = 629.63

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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.