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Finding the Fourth Proportional to 663.87, 990.93 and 615

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Solution

The fourth proportional to 663.87, 990.93 and 615 is: 917.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    663.87 : 990.93 = 615 : x
  2. Step 2: Convert to fraction form
    663.87/990.93 = 615/x
  3. Step 3: Cross multiply
    663.87x = 990.93 × 615
  4. Step 4: Simplify right side
    663.87x = 609,421.95
  5. Step 5: Solve for x
    x = 609,421.95/663.87
  6. Step 6: Final answer
    x = 917.98

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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.