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Finding the Fourth Proportional to 812.10, 1,217.58 and 649.74

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Solution

The fourth proportional to 812.10, 1,217.58 and 649.74 is: 974.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.10 : 1,217.58 = 649.74 : x
  2. Step 2: Convert to fraction form
    812.10/1,217.58 = 649.74/x
  3. Step 3: Cross multiply
    812.10x = 1,217.58 × 649.74
  4. Step 4: Simplify right side
    812.10x = 791,110.43
  5. Step 5: Solve for x
    x = 791,110.43/812.10
  6. Step 6: Final answer
    x = 974.15

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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.