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Finding the Fourth Proportional to 611.91, 917.20 and 265.40

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Solution

The fourth proportional to 611.91, 917.20 and 265.40 is: 397.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    611.91 : 917.20 = 265.40 : x
  2. Step 2: Convert to fraction form
    611.91/917.20 = 265.40/x
  3. Step 3: Cross multiply
    611.91x = 917.20 × 265.40
  4. Step 4: Simplify right side
    611.91x = 243,424.88
  5. Step 5: Solve for x
    x = 243,424.88/611.91
  6. Step 6: Final answer
    x = 397.81

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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.