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Finding the Fourth Proportional to 309.10, 427 and 274.28

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Solution

The fourth proportional to 309.10, 427 and 274.28 is: 378.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.10 : 427 = 274.28 : x
  2. Step 2: Convert to fraction form
    309.10/427 = 274.28/x
  3. Step 3: Cross multiply
    309.10x = 427 × 274.28
  4. Step 4: Simplify right side
    309.10x = 117,117.56
  5. Step 5: Solve for x
    x = 117,117.56/309.10
  6. Step 6: Final answer
    x = 378.90

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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.