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Finding the Fourth Proportional to 390.87, 586.34 and 147.35

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Solution

The fourth proportional to 390.87, 586.34 and 147.35 is: 221.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.87 : 586.34 = 147.35 : x
  2. Step 2: Convert to fraction form
    390.87/586.34 = 147.35/x
  3. Step 3: Cross multiply
    390.87x = 586.34 × 147.35
  4. Step 4: Simplify right side
    390.87x = 86,396.46
  5. Step 5: Solve for x
    x = 86,396.46/390.87
  6. Step 6: Final answer
    x = 221.04

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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.