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Finding the Fourth Proportional to 649.90, 896.70 and 621.55

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Solution

The fourth proportional to 649.90, 896.70 and 621.55 is: 857.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    649.90 : 896.70 = 621.55 : x
  2. Step 2: Convert to fraction form
    649.90/896.70 = 621.55/x
  3. Step 3: Cross multiply
    649.90x = 896.70 × 621.55
  4. Step 4: Simplify right side
    649.90x = 557,343.89
  5. Step 5: Solve for x
    x = 557,343.89/649.90
  6. Step 6: Final answer
    x = 857.58

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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.