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Finding the Fourth Proportional to 870.60, 1,305.90 and 654.60

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Solution

The fourth proportional to 870.60, 1,305.90 and 654.60 is: 981.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.60 : 1,305.90 = 654.60 : x
  2. Step 2: Convert to fraction form
    870.60/1,305.90 = 654.60/x
  3. Step 3: Cross multiply
    870.60x = 1,305.90 × 654.60
  4. Step 4: Simplify right side
    870.60x = 854,842.14
  5. Step 5: Solve for x
    x = 854,842.14/870.60
  6. Step 6: Final answer
    x = 981.90

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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.