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Finding the Fourth Proportional to 613.21, 921.75 and 511.15

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Solution

The fourth proportional to 613.21, 921.75 and 511.15 is: 768.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    613.21 : 921.75 = 511.15 : x
  2. Step 2: Convert to fraction form
    613.21/921.75 = 511.15/x
  3. Step 3: Cross multiply
    613.21x = 921.75 × 511.15
  4. Step 4: Simplify right side
    613.21x = 471,152.51
  5. Step 5: Solve for x
    x = 471,152.51/613.21
  6. Step 6: Final answer
    x = 768.34

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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.