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Finding the Fourth Proportional to 1,288.91, 1,778.06 and 764.57

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Solution

The fourth proportional to 1,288.91, 1,778.06 and 764.57 is: 1,054.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,288.91 : 1,778.06 = 764.57 : x
  2. Step 2: Convert to fraction form
    1,288.91/1,778.06 = 764.57/x
  3. Step 3: Cross multiply
    1,288.91x = 1,778.06 × 764.57
  4. Step 4: Simplify right side
    1,288.91x = 1,359,438.62
  5. Step 5: Solve for x
    x = 1,359,438.62/1,288.91
  6. Step 6: Final answer
    x = 1,054.72

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.