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Finding the Fourth Proportional to 770.80, 1,063.38 and 491.02

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Solution

The fourth proportional to 770.80, 1,063.38 and 491.02 is: 677.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    770.80 : 1,063.38 = 491.02 : x
  2. Step 2: Convert to fraction form
    770.80/1,063.38 = 491.02/x
  3. Step 3: Cross multiply
    770.80x = 1,063.38 × 491.02
  4. Step 4: Simplify right side
    770.80x = 522,140.85
  5. Step 5: Solve for x
    x = 522,140.85/770.80
  6. Step 6: Final answer
    x = 677.40

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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.