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Finding the Fourth Proportional to 1,987.46, 2,980.52 and 688.62

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Solution

The fourth proportional to 1,987.46, 2,980.52 and 688.62 is: 1,032.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,987.46 : 2,980.52 = 688.62 : x
  2. Step 2: Convert to fraction form
    1,987.46/2,980.52 = 688.62/x
  3. Step 3: Cross multiply
    1,987.46x = 2,980.52 × 688.62
  4. Step 4: Simplify right side
    1,987.46x = 2,052,445.68
  5. Step 5: Solve for x
    x = 2,052,445.68/1,987.46
  6. Step 6: Final answer
    x = 1,032.70

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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.