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Finding the Fourth Proportional to 521.90, 720.20 and 289.02

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Solution

The fourth proportional to 521.90, 720.20 and 289.02 is: 398.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.90 : 720.20 = 289.02 : x
  2. Step 2: Convert to fraction form
    521.90/720.20 = 289.02/x
  3. Step 3: Cross multiply
    521.90x = 720.20 × 289.02
  4. Step 4: Simplify right side
    521.90x = 208,152.93
  5. Step 5: Solve for x
    x = 208,152.93/521.90
  6. Step 6: Final answer
    x = 398.84

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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.