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Finding the Fourth Proportional to 1,687.32, 2,528.78 and 865.80

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Solution

The fourth proportional to 1,687.32, 2,528.78 and 865.80 is: 1,297.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,687.32 : 2,528.78 = 865.80 : x
  2. Step 2: Convert to fraction form
    1,687.32/2,528.78 = 865.80/x
  3. Step 3: Cross multiply
    1,687.32x = 2,528.78 × 865.80
  4. Step 4: Simplify right side
    1,687.32x = 2,189,417.72
  5. Step 5: Solve for x
    x = 2,189,417.72/1,687.32
  6. Step 6: Final answer
    x = 1,297.57

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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.