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Finding the Fourth Proportional to 390.22, 538.14 and 280.24

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Solution

The fourth proportional to 390.22, 538.14 and 280.24 is: 386.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.22 : 538.14 = 280.24 : x
  2. Step 2: Convert to fraction form
    390.22/538.14 = 280.24/x
  3. Step 3: Cross multiply
    390.22x = 538.14 × 280.24
  4. Step 4: Simplify right side
    390.22x = 150,808.35
  5. Step 5: Solve for x
    x = 150,808.35/390.22
  6. Step 6: Final answer
    x = 386.47

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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.