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Finding the Fourth Proportional to 810.85, 1,118.95 and 479.31

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Solution

The fourth proportional to 810.85, 1,118.95 and 479.31 is: 661.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.85 : 1,118.95 = 479.31 : x
  2. Step 2: Convert to fraction form
    810.85/1,118.95 = 479.31/x
  3. Step 3: Cross multiply
    810.85x = 1,118.95 × 479.31
  4. Step 4: Simplify right side
    810.85x = 536,323.92
  5. Step 5: Solve for x
    x = 536,323.92/810.85
  6. Step 6: Final answer
    x = 661.43

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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.