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Finding the Fourth Proportional to 440.40, 660.78 and 209.45

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Solution

The fourth proportional to 440.40, 660.78 and 209.45 is: 314.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    440.40 : 660.78 = 209.45 : x
  2. Step 2: Convert to fraction form
    440.40/660.78 = 209.45/x
  3. Step 3: Cross multiply
    440.40x = 660.78 × 209.45
  4. Step 4: Simplify right side
    440.40x = 138,397.07
  5. Step 5: Solve for x
    x = 138,397.07/440.40
  6. Step 6: Final answer
    x = 314.25

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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.