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Finding the Fourth Proportional to 611.40, 917.31 and 286.79

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Solution

The fourth proportional to 611.40, 917.31 and 286.79 is: 430.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    611.40 : 917.31 = 286.79 : x
  2. Step 2: Convert to fraction form
    611.40/917.31 = 286.79/x
  3. Step 3: Cross multiply
    611.40x = 917.31 × 286.79
  4. Step 4: Simplify right side
    611.40x = 263,070.75
  5. Step 5: Solve for x
    x = 263,070.75/611.40
  6. Step 6: Final answer
    x = 430.28

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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.