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Finding the Fourth Proportional to 770.60, 1,156.41 and 405.65

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Solution

The fourth proportional to 770.60, 1,156.41 and 405.65 is: 608.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    770.60 : 1,156.41 = 405.65 : x
  2. Step 2: Convert to fraction form
    770.60/1,156.41 = 405.65/x
  3. Step 3: Cross multiply
    770.60x = 1,156.41 × 405.65
  4. Step 4: Simplify right side
    770.60x = 469,091.93
  5. Step 5: Solve for x
    x = 469,091.93/770.60
  6. Step 6: Final answer
    x = 608.74

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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.