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Finding the Fourth Proportional to 659.64, 990.42 and 648.72

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Solution

The fourth proportional to 659.64, 990.42 and 648.72 is: 974.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.64 : 990.42 = 648.72 : x
  2. Step 2: Convert to fraction form
    659.64/990.42 = 648.72/x
  3. Step 3: Cross multiply
    659.64x = 990.42 × 648.72
  4. Step 4: Simplify right side
    659.64x = 642,505.26
  5. Step 5: Solve for x
    x = 642,505.26/659.64
  6. Step 6: Final answer
    x = 974.02

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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.