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Finding the Fourth Proportional to 612.80, 845.76 and 438.72

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Solution

The fourth proportional to 612.80, 845.76 and 438.72 is: 605.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    612.80 : 845.76 = 438.72 : x
  2. Step 2: Convert to fraction form
    612.80/845.76 = 438.72/x
  3. Step 3: Cross multiply
    612.80x = 845.76 × 438.72
  4. Step 4: Simplify right side
    612.80x = 371,051.83
  5. Step 5: Solve for x
    x = 371,051.83/612.80
  6. Step 6: Final answer
    x = 605.50

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.