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Finding the Fourth Proportional to 898.72, 1,239.82 and 649.64

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Solution

The fourth proportional to 898.72, 1,239.82 and 649.64 is: 896.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    898.72 : 1,239.82 = 649.64 : x
  2. Step 2: Convert to fraction form
    898.72/1,239.82 = 649.64/x
  3. Step 3: Cross multiply
    898.72x = 1,239.82 × 649.64
  4. Step 4: Simplify right side
    898.72x = 805,438.14
  5. Step 5: Solve for x
    x = 805,438.14/898.72
  6. Step 6: Final answer
    x = 896.21

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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.