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Finding the Fourth Proportional to 770.12, 1,062.78 and 420.82

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Solution

The fourth proportional to 770.12, 1,062.78 and 420.82 is: 580.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    770.12 : 1,062.78 = 420.82 : x
  2. Step 2: Convert to fraction form
    770.12/1,062.78 = 420.82/x
  3. Step 3: Cross multiply
    770.12x = 1,062.78 × 420.82
  4. Step 4: Simplify right side
    770.12x = 447,239.08
  5. Step 5: Solve for x
    x = 447,239.08/770.12
  6. Step 6: Final answer
    x = 580.74

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.