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Finding the Fourth Proportional to 390.09, 538.40 and 224.32

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Solution

The fourth proportional to 390.09, 538.40 and 224.32 is: 309.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.09 : 538.40 = 224.32 : x
  2. Step 2: Convert to fraction form
    390.09/538.40 = 224.32/x
  3. Step 3: Cross multiply
    390.09x = 538.40 × 224.32
  4. Step 4: Simplify right side
    390.09x = 120,772.85
  5. Step 5: Solve for x
    x = 120,772.85/390.09
  6. Step 6: Final answer
    x = 309.60

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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.