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Finding the Fourth Proportional to 869.40, 1,200.05 and 515.30

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Solution

The fourth proportional to 869.40, 1,200.05 and 515.30 is: 711.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    869.40 : 1,200.05 = 515.30 : x
  2. Step 2: Convert to fraction form
    869.40/1,200.05 = 515.30/x
  3. Step 3: Cross multiply
    869.40x = 1,200.05 × 515.30
  4. Step 4: Simplify right side
    869.40x = 618,377.19
  5. Step 5: Solve for x
    x = 618,377.19/869.40
  6. Step 6: Final answer
    x = 711.27

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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.