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Finding the Fourth Proportional to 390.70, 538.96 and 284.24

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Solution

The fourth proportional to 390.70, 538.96 and 284.24 is: 392.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.70 : 538.96 = 284.24 : x
  2. Step 2: Convert to fraction form
    390.70/538.96 = 284.24/x
  3. Step 3: Cross multiply
    390.70x = 538.96 × 284.24
  4. Step 4: Simplify right side
    390.70x = 153,191.47
  5. Step 5: Solve for x
    x = 153,191.47/390.70
  6. Step 6: Final answer
    x = 392.10

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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.