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Finding the Fourth Proportional to 309.86, 430.61 and 305.99

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Solution

The fourth proportional to 309.86, 430.61 and 305.99 is: 425.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.86 : 430.61 = 305.99 : x
  2. Step 2: Convert to fraction form
    309.86/430.61 = 305.99/x
  3. Step 3: Cross multiply
    309.86x = 430.61 × 305.99
  4. Step 4: Simplify right side
    309.86x = 131,762.35
  5. Step 5: Solve for x
    x = 131,762.35/309.86
  6. Step 6: Final answer
    x = 425.23

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.