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Finding the Fourth Proportional to 661.97, 988.18 and 613.90

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Solution

The fourth proportional to 661.97, 988.18 and 613.90 is: 916.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.97 : 988.18 = 613.90 : x
  2. Step 2: Convert to fraction form
    661.97/988.18 = 613.90/x
  3. Step 3: Cross multiply
    661.97x = 988.18 × 613.90
  4. Step 4: Simplify right side
    661.97x = 606,641.30
  5. Step 5: Solve for x
    x = 606,641.30/661.97
  6. Step 6: Final answer
    x = 916.42

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.