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Finding the Fourth Proportional to 479.16, 660.48 and 391

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Solution

The fourth proportional to 479.16, 660.48 and 391 is: 538.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    479.16 : 660.48 = 391 : x
  2. Step 2: Convert to fraction form
    479.16/660.48 = 391/x
  3. Step 3: Cross multiply
    479.16x = 660.48 × 391
  4. Step 4: Simplify right side
    479.16x = 258,247.68
  5. Step 5: Solve for x
    x = 258,247.68/479.16
  6. Step 6: Final answer
    x = 538.96

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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.