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Finding the Fourth Proportional to 661.70, 991.85 and 418.30

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Solution

The fourth proportional to 661.70, 991.85 and 418.30 is: 627.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.70 : 991.85 = 418.30 : x
  2. Step 2: Convert to fraction form
    661.70/991.85 = 418.30/x
  3. Step 3: Cross multiply
    661.70x = 991.85 × 418.30
  4. Step 4: Simplify right side
    661.70x = 414,886.28
  5. Step 5: Solve for x
    x = 414,886.28/661.70
  6. Step 6: Final answer
    x = 627.00

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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.