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Finding the Fourth Proportional to 521.66, 719.91 and 288.78

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Solution

The fourth proportional to 521.66, 719.91 and 288.78 is: 398.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.66 : 719.91 = 288.78 : x
  2. Step 2: Convert to fraction form
    521.66/719.91 = 288.78/x
  3. Step 3: Cross multiply
    521.66x = 719.91 × 288.78
  4. Step 4: Simplify right side
    521.66x = 207,895.61
  5. Step 5: Solve for x
    x = 207,895.61/521.66
  6. Step 6: Final answer
    x = 398.53

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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.