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Finding the Fourth Proportional to 921.85, 1,272.13 and 502.21

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Solution

The fourth proportional to 921.85, 1,272.13 and 502.21 is: 693.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    921.85 : 1,272.13 = 502.21 : x
  2. Step 2: Convert to fraction form
    921.85/1,272.13 = 502.21/x
  3. Step 3: Cross multiply
    921.85x = 1,272.13 × 502.21
  4. Step 4: Simplify right side
    921.85x = 638,876.41
  5. Step 5: Solve for x
    x = 638,876.41/921.85
  6. Step 6: Final answer
    x = 693.04

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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.