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Finding the Fourth Proportional to 649.80, 896.48 and 387.78

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Solution

The fourth proportional to 649.80, 896.48 and 387.78 is: 534.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    649.80 : 896.48 = 387.78 : x
  2. Step 2: Convert to fraction form
    649.80/896.48 = 387.78/x
  3. Step 3: Cross multiply
    649.80x = 896.48 × 387.78
  4. Step 4: Simplify right side
    649.80x = 347,637.01
  5. Step 5: Solve for x
    x = 347,637.01/649.80
  6. Step 6: Final answer
    x = 534.99

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.