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Finding the Fourth Proportional to 648.89, 978.12 and 611.26

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Solution

The fourth proportional to 648.89, 978.12 and 611.26 is: 921.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    648.89 : 978.12 = 611.26 : x
  2. Step 2: Convert to fraction form
    648.89/978.12 = 611.26/x
  3. Step 3: Cross multiply
    648.89x = 978.12 × 611.26
  4. Step 4: Simplify right side
    648.89x = 597,883.19
  5. Step 5: Solve for x
    x = 597,883.19/648.89
  6. Step 6: Final answer
    x = 921.40

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.