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Finding the Fourth Proportional to 659.20, 988.80 and 654.40

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Solution

The fourth proportional to 659.20, 988.80 and 654.40 is: 981.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.20 : 988.80 = 654.40 : x
  2. Step 2: Convert to fraction form
    659.20/988.80 = 654.40/x
  3. Step 3: Cross multiply
    659.20x = 988.80 × 654.40
  4. Step 4: Simplify right side
    659.20x = 647,070.72
  5. Step 5: Solve for x
    x = 647,070.72/659.20
  6. Step 6: Final answer
    x = 981.60

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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.