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Finding the Fourth Proportional to 840.24, 1,259.15 and 407.70

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Solution

The fourth proportional to 840.24, 1,259.15 and 407.70 is: 610.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.24 : 1,259.15 = 407.70 : x
  2. Step 2: Convert to fraction form
    840.24/1,259.15 = 407.70/x
  3. Step 3: Cross multiply
    840.24x = 1,259.15 × 407.70
  4. Step 4: Simplify right side
    840.24x = 513,353.42
  5. Step 5: Solve for x
    x = 513,353.42/840.24
  6. Step 6: Final answer
    x = 610.96

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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.