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Finding the Fourth Proportional to 390.30, 537.89 and 291.89

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Solution

The fourth proportional to 390.30, 537.89 and 291.89 is: 402.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.30 : 537.89 = 291.89 : x
  2. Step 2: Convert to fraction form
    390.30/537.89 = 291.89/x
  3. Step 3: Cross multiply
    390.30x = 537.89 × 291.89
  4. Step 4: Simplify right side
    390.30x = 157,000.56
  5. Step 5: Solve for x
    x = 157,000.56/390.30
  6. Step 6: Final answer
    x = 402.26

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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.