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Finding the Fourth Proportional to 869.40, 1,304.10 and 861.30

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Solution

The fourth proportional to 869.40, 1,304.10 and 861.30 is: 1,291.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    869.40 : 1,304.10 = 861.30 : x
  2. Step 2: Convert to fraction form
    869.40/1,304.10 = 861.30/x
  3. Step 3: Cross multiply
    869.40x = 1,304.10 × 861.30
  4. Step 4: Simplify right side
    869.40x = 1,123,221.33
  5. Step 5: Solve for x
    x = 1,123,221.33/869.40
  6. Step 6: Final answer
    x = 1,291.95

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.