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Finding the Fourth Proportional to 1,288.46, 1,929.80 and 878.39

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Solution

The fourth proportional to 1,288.46, 1,929.80 and 878.39 is: 1,315.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,288.46 : 1,929.80 = 878.39 : x
  2. Step 2: Convert to fraction form
    1,288.46/1,929.80 = 878.39/x
  3. Step 3: Cross multiply
    1,288.46x = 1,929.80 × 878.39
  4. Step 4: Simplify right side
    1,288.46x = 1,695,102.98
  5. Step 5: Solve for x
    x = 1,695,102.98/1,288.46
  6. Step 6: Final answer
    x = 1,315.61

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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.