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Finding the Fourth Proportional to 660.70, 989.87 and 621.66

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Solution

The fourth proportional to 660.70, 989.87 and 621.66 is: 931.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.70 : 989.87 = 621.66 : x
  2. Step 2: Convert to fraction form
    660.70/989.87 = 621.66/x
  3. Step 3: Cross multiply
    660.70x = 989.87 × 621.66
  4. Step 4: Simplify right side
    660.70x = 615,363.19
  5. Step 5: Solve for x
    x = 615,363.19/660.70
  6. Step 6: Final answer
    x = 931.38

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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.