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Finding the Fourth Proportional to 390.02, 538.21 and 212.99

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Solution

The fourth proportional to 390.02, 538.21 and 212.99 is: 293.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.02 : 538.21 = 212.99 : x
  2. Step 2: Convert to fraction form
    390.02/538.21 = 212.99/x
  3. Step 3: Cross multiply
    390.02x = 538.21 × 212.99
  4. Step 4: Simplify right side
    390.02x = 114,630.92
  5. Step 5: Solve for x
    x = 114,630.92/390.02
  6. Step 6: Final answer
    x = 293.91

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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.