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Finding the Fourth Proportional to 647.72, 971.48 and 214.78

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Solution

The fourth proportional to 647.72, 971.48 and 214.78 is: 322.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    647.72 : 971.48 = 214.78 : x
  2. Step 2: Convert to fraction form
    647.72/971.48 = 214.78/x
  3. Step 3: Cross multiply
    647.72x = 971.48 × 214.78
  4. Step 4: Simplify right side
    647.72x = 208,654.47
  5. Step 5: Solve for x
    x = 208,654.47/647.72
  6. Step 6: Final answer
    x = 322.14

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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.