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Finding the Fourth Proportional to 649.36, 972.78 and 389.58

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Solution

The fourth proportional to 649.36, 972.78 and 389.58 is: 583.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    649.36 : 972.78 = 389.58 : x
  2. Step 2: Convert to fraction form
    649.36/972.78 = 389.58/x
  3. Step 3: Cross multiply
    649.36x = 972.78 × 389.58
  4. Step 4: Simplify right side
    649.36x = 378,973.68
  5. Step 5: Solve for x
    x = 378,973.68/649.36
  6. Step 6: Final answer
    x = 583.61

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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.