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Finding the Fourth Proportional to 521.50, 719.63 and 285.40

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Solution

The fourth proportional to 521.50, 719.63 and 285.40 is: 393.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.50 : 719.63 = 285.40 : x
  2. Step 2: Convert to fraction form
    521.50/719.63 = 285.40/x
  3. Step 3: Cross multiply
    521.50x = 719.63 × 285.40
  4. Step 4: Simplify right side
    521.50x = 205,378.80
  5. Step 5: Solve for x
    x = 205,378.80/521.50
  6. Step 6: Final answer
    x = 393.83

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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.