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Finding the Fourth Proportional to 865.14, 1,298.40 and 660.21

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Solution

The fourth proportional to 865.14, 1,298.40 and 660.21 is: 990.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    865.14 : 1,298.40 = 660.21 : x
  2. Step 2: Convert to fraction form
    865.14/1,298.40 = 660.21/x
  3. Step 3: Cross multiply
    865.14x = 1,298.40 × 660.21
  4. Step 4: Simplify right side
    865.14x = 857,216.66
  5. Step 5: Solve for x
    x = 857,216.66/865.14
  6. Step 6: Final answer
    x = 990.84

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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.