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Finding the Fourth Proportional to 612.21, 917.10 and 521.10

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Solution

The fourth proportional to 612.21, 917.10 and 521.10 is: 780.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    612.21 : 917.10 = 521.10 : x
  2. Step 2: Convert to fraction form
    612.21/917.10 = 521.10/x
  3. Step 3: Cross multiply
    612.21x = 917.10 × 521.10
  4. Step 4: Simplify right side
    612.21x = 477,900.81
  5. Step 5: Solve for x
    x = 477,900.81/612.21
  6. Step 6: Final answer
    x = 780.62

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.