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Finding the Fourth Proportional to 649.55, 896.40 and 387.72

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Solution

The fourth proportional to 649.55, 896.40 and 387.72 is: 535.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    649.55 : 896.40 = 387.72 : x
  2. Step 2: Convert to fraction form
    649.55/896.40 = 387.72/x
  3. Step 3: Cross multiply
    649.55x = 896.40 × 387.72
  4. Step 4: Simplify right side
    649.55x = 347,552.21
  5. Step 5: Solve for x
    x = 347,552.21/649.55
  6. Step 6: Final answer
    x = 535.06

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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.