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Finding the Fourth Proportional to 905.10, 1,248.90 and 512.05

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Solution

The fourth proportional to 905.10, 1,248.90 and 512.05 is: 706.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    905.10 : 1,248.90 = 512.05 : x
  2. Step 2: Convert to fraction form
    905.10/1,248.90 = 512.05/x
  3. Step 3: Cross multiply
    905.10x = 1,248.90 × 512.05
  4. Step 4: Simplify right side
    905.10x = 639,499.25
  5. Step 5: Solve for x
    x = 639,499.25/905.10
  6. Step 6: Final answer
    x = 706.55

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.