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Finding the Fourth Proportional to 521.81, 720.15 and 288.94

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Solution

The fourth proportional to 521.81, 720.15 and 288.94 is: 398.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.81 : 720.15 = 288.94 : x
  2. Step 2: Convert to fraction form
    521.81/720.15 = 288.94/x
  3. Step 3: Cross multiply
    521.81x = 720.15 × 288.94
  4. Step 4: Simplify right side
    521.81x = 208,079.42
  5. Step 5: Solve for x
    x = 208,079.42/521.81
  6. Step 6: Final answer
    x = 398.76

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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.