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Finding the Fourth Proportional to 660.42, 990.65 and 313.68

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Solution

The fourth proportional to 660.42, 990.65 and 313.68 is: 470.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.42 : 990.65 = 313.68 : x
  2. Step 2: Convert to fraction form
    660.42/990.65 = 313.68/x
  3. Step 3: Cross multiply
    660.42x = 990.65 × 313.68
  4. Step 4: Simplify right side
    660.42x = 310,747.09
  5. Step 5: Solve for x
    x = 310,747.09/660.42
  6. Step 6: Final answer
    x = 470.53

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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.