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Finding the Fourth Proportional to 869.39, 1,305.50 and 805.40

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Solution

The fourth proportional to 869.39, 1,305.50 and 805.40 is: 1,209.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    869.39 : 1,305.50 = 805.40 : x
  2. Step 2: Convert to fraction form
    869.39/1,305.50 = 805.40/x
  3. Step 3: Cross multiply
    869.39x = 1,305.50 × 805.40
  4. Step 4: Simplify right side
    869.39x = 1,051,439.15
  5. Step 5: Solve for x
    x = 1,051,439.15/869.39
  6. Step 6: Final answer
    x = 1,209.41

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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.