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Finding the Fourth Proportional to 647.81, 971.86 and 339.60

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Solution

The fourth proportional to 647.81, 971.86 and 339.60 is: 509.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    647.81 : 971.86 = 339.60 : x
  2. Step 2: Convert to fraction form
    647.81/971.86 = 339.60/x
  3. Step 3: Cross multiply
    647.81x = 971.86 × 339.60
  4. Step 4: Simplify right side
    647.81x = 330,043.66
  5. Step 5: Solve for x
    x = 330,043.66/647.81
  6. Step 6: Final answer
    x = 509.48

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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.