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Finding the Fourth Proportional to 645.12, 971.12 and 555.80

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Solution

The fourth proportional to 645.12, 971.12 and 555.80 is: 836.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.12 : 971.12 = 555.80 : x
  2. Step 2: Convert to fraction form
    645.12/971.12 = 555.80/x
  3. Step 3: Cross multiply
    645.12x = 971.12 × 555.80
  4. Step 4: Simplify right side
    645.12x = 539,748.50
  5. Step 5: Solve for x
    x = 539,748.50/645.12
  6. Step 6: Final answer
    x = 836.66

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.