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Finding the Fourth Proportional to 660.31, 990.53 and 313.81

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Solution

The fourth proportional to 660.31, 990.53 and 313.81 is: 470.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.31 : 990.53 = 313.81 : x
  2. Step 2: Convert to fraction form
    660.31/990.53 = 313.81/x
  3. Step 3: Cross multiply
    660.31x = 990.53 × 313.81
  4. Step 4: Simplify right side
    660.31x = 310,839.53
  5. Step 5: Solve for x
    x = 310,839.53/660.31
  6. Step 6: Final answer
    x = 470.74

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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.