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Finding the Fourth Proportional to 489.60, 729.60 and 446.40

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Solution

The fourth proportional to 489.60, 729.60 and 446.40 is: 665.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    489.60 : 729.60 = 446.40 : x
  2. Step 2: Convert to fraction form
    489.60/729.60 = 446.40/x
  3. Step 3: Cross multiply
    489.60x = 729.60 × 446.40
  4. Step 4: Simplify right side
    489.60x = 325,693.44
  5. Step 5: Solve for x
    x = 325,693.44/489.60
  6. Step 6: Final answer
    x = 665.22

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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.