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Finding the Fourth Proportional to 840.30, 1,260.45 and 764.70

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Solution

The fourth proportional to 840.30, 1,260.45 and 764.70 is: 1,147.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.30 : 1,260.45 = 764.70 : x
  2. Step 2: Convert to fraction form
    840.30/1,260.45 = 764.70/x
  3. Step 3: Cross multiply
    840.30x = 1,260.45 × 764.70
  4. Step 4: Simplify right side
    840.30x = 963,866.12
  5. Step 5: Solve for x
    x = 963,866.12/840.30
  6. Step 6: Final answer
    x = 1,147.05

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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.