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Finding the Fourth Proportional to 770.07, 1,062.71 and 420.78

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Solution

The fourth proportional to 770.07, 1,062.71 and 420.78 is: 580.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    770.07 : 1,062.71 = 420.78 : x
  2. Step 2: Convert to fraction form
    770.07/1,062.71 = 420.78/x
  3. Step 3: Cross multiply
    770.07x = 1,062.71 × 420.78
  4. Step 4: Simplify right side
    770.07x = 447,165.01
  5. Step 5: Solve for x
    x = 447,165.01/770.07
  6. Step 6: Final answer
    x = 580.68

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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.