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Finding the Fourth Proportional to 620.69, 931.46 and 458.78

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Solution

The fourth proportional to 620.69, 931.46 and 458.78 is: 688.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.69 : 931.46 = 458.78 : x
  2. Step 2: Convert to fraction form
    620.69/931.46 = 458.78/x
  3. Step 3: Cross multiply
    620.69x = 931.46 × 458.78
  4. Step 4: Simplify right side
    620.69x = 427,328.27
  5. Step 5: Solve for x
    x = 427,328.27/620.69
  6. Step 6: Final answer
    x = 688.48

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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.