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Finding the Fourth Proportional to 390.50, 538.90 and 235.26

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Solution

The fourth proportional to 390.50, 538.90 and 235.26 is: 324.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.50 : 538.90 = 235.26 : x
  2. Step 2: Convert to fraction form
    390.50/538.90 = 235.26/x
  3. Step 3: Cross multiply
    390.50x = 538.90 × 235.26
  4. Step 4: Simplify right side
    390.50x = 126,781.61
  5. Step 5: Solve for x
    x = 126,781.61/390.50
  6. Step 6: Final answer
    x = 324.66

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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.