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Finding the Fourth Proportional to 1,707.96, 2,557.44 and 840

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Solution

The fourth proportional to 1,707.96, 2,557.44 and 840 is: 1,257.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,707.96 : 2,557.44 = 840 : x
  2. Step 2: Convert to fraction form
    1,707.96/2,557.44 = 840/x
  3. Step 3: Cross multiply
    1,707.96x = 2,557.44 × 840
  4. Step 4: Simplify right side
    1,707.96x = 2,148,249.60
  5. Step 5: Solve for x
    x = 2,148,249.60/1,707.96
  6. Step 6: Final answer
    x = 1,257.79

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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.