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Finding the Fourth Proportional to 390.85, 586.15 and 193.07

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Solution

The fourth proportional to 390.85, 586.15 and 193.07 is: 289.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.85 : 586.15 = 193.07 : x
  2. Step 2: Convert to fraction form
    390.85/586.15 = 193.07/x
  3. Step 3: Cross multiply
    390.85x = 586.15 × 193.07
  4. Step 4: Simplify right side
    390.85x = 113,168.96
  5. Step 5: Solve for x
    x = 113,168.96/390.85
  6. Step 6: Final answer
    x = 289.55

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.