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Finding the Fourth Proportional to 770.85, 1,063.78 and 421.53

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Solution

The fourth proportional to 770.85, 1,063.78 and 421.53 is: 581.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    770.85 : 1,063.78 = 421.53 : x
  2. Step 2: Convert to fraction form
    770.85/1,063.78 = 421.53/x
  3. Step 3: Cross multiply
    770.85x = 1,063.78 × 421.53
  4. Step 4: Simplify right side
    770.85x = 448,415.18
  5. Step 5: Solve for x
    x = 448,415.18/770.85
  6. Step 6: Final answer
    x = 581.72

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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.