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Finding the Fourth Proportional to 869.64, 1,200.05 and 515.55

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Solution

The fourth proportional to 869.64, 1,200.05 and 515.55 is: 711.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    869.64 : 1,200.05 = 515.55 : x
  2. Step 2: Convert to fraction form
    869.64/1,200.05 = 515.55/x
  3. Step 3: Cross multiply
    869.64x = 1,200.05 × 515.55
  4. Step 4: Simplify right side
    869.64x = 618,685.78
  5. Step 5: Solve for x
    x = 618,685.78/869.64
  6. Step 6: Final answer
    x = 711.43

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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.