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Finding the Fourth Proportional to 309.47, 427.07 and 198.91

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Solution

The fourth proportional to 309.47, 427.07 and 198.91 is: 274.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.47 : 427.07 = 198.91 : x
  2. Step 2: Convert to fraction form
    309.47/427.07 = 198.91/x
  3. Step 3: Cross multiply
    309.47x = 427.07 × 198.91
  4. Step 4: Simplify right side
    309.47x = 84,948.49
  5. Step 5: Solve for x
    x = 84,948.49/309.47
  6. Step 6: Final answer
    x = 274.50

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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.