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Finding the Fourth Proportional to 786.08, 1,179.36 and 420.89

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Solution

The fourth proportional to 786.08, 1,179.36 and 420.89 is: 631.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    786.08 : 1,179.36 = 420.89 : x
  2. Step 2: Convert to fraction form
    786.08/1,179.36 = 420.89/x
  3. Step 3: Cross multiply
    786.08x = 1,179.36 × 420.89
  4. Step 4: Simplify right side
    786.08x = 496,380.83
  5. Step 5: Solve for x
    x = 496,380.83/786.08
  6. Step 6: Final answer
    x = 631.46

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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.