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Finding the Fourth Proportional to 347.78, 479.80 and 309.91

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Solution

The fourth proportional to 347.78, 479.80 and 309.91 is: 427.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    347.78 : 479.80 = 309.91 : x
  2. Step 2: Convert to fraction form
    347.78/479.80 = 309.91/x
  3. Step 3: Cross multiply
    347.78x = 479.80 × 309.91
  4. Step 4: Simplify right side
    347.78x = 148,694.82
  5. Step 5: Solve for x
    x = 148,694.82/347.78
  6. Step 6: Final answer
    x = 427.55

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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.