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Finding the Fourth Proportional to 649.78, 896.75 and 387.79

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Solution

The fourth proportional to 649.78, 896.75 and 387.79 is: 535.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    649.78 : 896.75 = 387.79 : x
  2. Step 2: Convert to fraction form
    649.78/896.75 = 387.79/x
  3. Step 3: Cross multiply
    649.78x = 896.75 × 387.79
  4. Step 4: Simplify right side
    649.78x = 347,748.74
  5. Step 5: Solve for x
    x = 347,748.74/649.78
  6. Step 6: Final answer
    x = 535.18

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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.