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Finding the Fourth Proportional to 390.32, 585.40 and 146.80

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Solution

The fourth proportional to 390.32, 585.40 and 146.80 is: 220.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.32 : 585.40 = 146.80 : x
  2. Step 2: Convert to fraction form
    390.32/585.40 = 146.80/x
  3. Step 3: Cross multiply
    390.32x = 585.40 × 146.80
  4. Step 4: Simplify right side
    390.32x = 85,936.72
  5. Step 5: Solve for x
    x = 85,936.72/390.32
  6. Step 6: Final answer
    x = 220.17

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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.