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Finding the Fourth Proportional to 649.69, 974.78 and 389.88

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Solution

The fourth proportional to 649.69, 974.78 and 389.88 is: 584.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    649.69 : 974.78 = 389.88 : x
  2. Step 2: Convert to fraction form
    649.69/974.78 = 389.88/x
  3. Step 3: Cross multiply
    649.69x = 974.78 × 389.88
  4. Step 4: Simplify right side
    649.69x = 380,047.10
  5. Step 5: Solve for x
    x = 380,047.10/649.69
  6. Step 6: Final answer
    x = 584.96

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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.