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Finding the Fourth Proportional to 621.60, 872.40 and 621.60

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Solution

The fourth proportional to 621.60, 872.40 and 621.60 is: 872.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.60 : 872.40 = 621.60 : x
  2. Step 2: Convert to fraction form
    621.60/872.40 = 621.60/x
  3. Step 3: Cross multiply
    621.60x = 872.40 × 621.60
  4. Step 4: Simplify right side
    621.60x = 542,283.84
  5. Step 5: Solve for x
    x = 542,283.84/621.60
  6. Step 6: Final answer
    x = 872.40

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Why These Related Problems?

These problems maintain the same ratio (1.40) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.