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Finding the Fourth Proportional to 648.40, 972.56 and 258.60

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Solution

The fourth proportional to 648.40, 972.56 and 258.60 is: 387.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    648.40 : 972.56 = 258.60 : x
  2. Step 2: Convert to fraction form
    648.40/972.56 = 258.60/x
  3. Step 3: Cross multiply
    648.40x = 972.56 × 258.60
  4. Step 4: Simplify right side
    648.40x = 251,504.02
  5. Step 5: Solve for x
    x = 251,504.02/648.40
  6. Step 6: Final answer
    x = 387.88

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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.