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Finding the Fourth Proportional to 770.25, 1,155.86 and 405.30

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Solution

The fourth proportional to 770.25, 1,155.86 and 405.30 is: 608.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    770.25 : 1,155.86 = 405.30 : x
  2. Step 2: Convert to fraction form
    770.25/1,155.86 = 405.30/x
  3. Step 3: Cross multiply
    770.25x = 1,155.86 × 405.30
  4. Step 4: Simplify right side
    770.25x = 468,468.03
  5. Step 5: Solve for x
    x = 468,468.03/770.25
  6. Step 6: Final answer
    x = 608.20

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.