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Finding the Fourth Proportional to 309.60, 423.72 and 306.36

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Solution

The fourth proportional to 309.60, 423.72 and 306.36 is: 419.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.60 : 423.72 = 306.36 : x
  2. Step 2: Convert to fraction form
    309.60/423.72 = 306.36/x
  3. Step 3: Cross multiply
    309.60x = 423.72 × 306.36
  4. Step 4: Simplify right side
    309.60x = 129,810.86
  5. Step 5: Solve for x
    x = 129,810.86/309.60
  6. Step 6: Final answer
    x = 419.29

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.