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Finding the Fourth Proportional to 390.90, 586.35 and 147.48

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Solution

The fourth proportional to 390.90, 586.35 and 147.48 is: 221.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.90 : 586.35 = 147.48 : x
  2. Step 2: Convert to fraction form
    390.90/586.35 = 147.48/x
  3. Step 3: Cross multiply
    390.90x = 586.35 × 147.48
  4. Step 4: Simplify right side
    390.90x = 86,474.90
  5. Step 5: Solve for x
    x = 86,474.90/390.90
  6. Step 6: Final answer
    x = 221.22

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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.