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Finding the Fourth Proportional to 390.84, 539.28 and 235.50

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Solution

The fourth proportional to 390.84, 539.28 and 235.50 is: 324.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.84 : 539.28 = 235.50 : x
  2. Step 2: Convert to fraction form
    390.84/539.28 = 235.50/x
  3. Step 3: Cross multiply
    390.84x = 539.28 × 235.50
  4. Step 4: Simplify right side
    390.84x = 127,000.44
  5. Step 5: Solve for x
    x = 127,000.44/390.84
  6. Step 6: Final answer
    x = 324.94

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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.