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Finding the Fourth Proportional to 921.09, 1,271.11 and 507.09

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Solution

The fourth proportional to 921.09, 1,271.11 and 507.09 is: 699.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    921.09 : 1,271.11 = 507.09 : x
  2. Step 2: Convert to fraction form
    921.09/1,271.11 = 507.09/x
  3. Step 3: Cross multiply
    921.09x = 1,271.11 × 507.09
  4. Step 4: Simplify right side
    921.09x = 644,567.17
  5. Step 5: Solve for x
    x = 644,567.17/921.09
  6. Step 6: Final answer
    x = 699.79

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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.