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Finding the Fourth Proportional to 390.21, 538.47 and 222.14

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Solution

The fourth proportional to 390.21, 538.47 and 222.14 is: 306.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.21 : 538.47 = 222.14 : x
  2. Step 2: Convert to fraction form
    390.21/538.47 = 222.14/x
  3. Step 3: Cross multiply
    390.21x = 538.47 × 222.14
  4. Step 4: Simplify right side
    390.21x = 119,613.03
  5. Step 5: Solve for x
    x = 119,613.03/390.21
  6. Step 6: Final answer
    x = 306.54

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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.