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Finding the Fourth Proportional to 611.81, 917.85 and 287

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Solution

The fourth proportional to 611.81, 917.85 and 287 is: 430.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    611.81 : 917.85 = 287 : x
  2. Step 2: Convert to fraction form
    611.81/917.85 = 287/x
  3. Step 3: Cross multiply
    611.81x = 917.85 × 287
  4. Step 4: Simplify right side
    611.81x = 263,422.95
  5. Step 5: Solve for x
    x = 263,422.95/611.81
  6. Step 6: Final answer
    x = 430.56

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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.