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Finding the Fourth Proportional to 647.42, 971.19 and 208.56

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Solution

The fourth proportional to 647.42, 971.19 and 208.56 is: 312.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    647.42 : 971.19 = 208.56 : x
  2. Step 2: Convert to fraction form
    647.42/971.19 = 208.56/x
  3. Step 3: Cross multiply
    647.42x = 971.19 × 208.56
  4. Step 4: Simplify right side
    647.42x = 202,549.57
  5. Step 5: Solve for x
    x = 202,549.57/647.42
  6. Step 6: Final answer
    x = 312.86

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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.