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Finding the Fourth Proportional to 870.09, 1,305.45 and 431.52

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Solution

The fourth proportional to 870.09, 1,305.45 and 431.52 is: 647.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.09 : 1,305.45 = 431.52 : x
  2. Step 2: Convert to fraction form
    870.09/1,305.45 = 431.52/x
  3. Step 3: Cross multiply
    870.09x = 1,305.45 × 431.52
  4. Step 4: Simplify right side
    870.09x = 563,327.78
  5. Step 5: Solve for x
    x = 563,327.78/870.09
  6. Step 6: Final answer
    x = 647.44

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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.