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Finding the Fourth Proportional to 688.72, 1,033.80 and 649.12

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Solution

The fourth proportional to 688.72, 1,033.80 and 649.12 is: 974.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.72 : 1,033.80 = 649.12 : x
  2. Step 2: Convert to fraction form
    688.72/1,033.80 = 649.12/x
  3. Step 3: Cross multiply
    688.72x = 1,033.80 × 649.12
  4. Step 4: Simplify right side
    688.72x = 671,060.26
  5. Step 5: Solve for x
    x = 671,060.26/688.72
  6. Step 6: Final answer
    x = 974.36

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.