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Finding the Fourth Proportional to 648.40, 971.53 and 339.79

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Solution

The fourth proportional to 648.40, 971.53 and 339.79 is: 509.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    648.40 : 971.53 = 339.79 : x
  2. Step 2: Convert to fraction form
    648.40/971.53 = 339.79/x
  3. Step 3: Cross multiply
    648.40x = 971.53 × 339.79
  4. Step 4: Simplify right side
    648.40x = 330,116.18
  5. Step 5: Solve for x
    x = 330,116.18/648.40
  6. Step 6: Final answer
    x = 509.12

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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.