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Finding the Fourth Proportional to 770.94, 1,156.80 and 405.80

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Solution

The fourth proportional to 770.94, 1,156.80 and 405.80 is: 608.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    770.94 : 1,156.80 = 405.80 : x
  2. Step 2: Convert to fraction form
    770.94/1,156.80 = 405.80/x
  3. Step 3: Cross multiply
    770.94x = 1,156.80 × 405.80
  4. Step 4: Simplify right side
    770.94x = 469,423.66
  5. Step 5: Solve for x
    x = 469,423.66/770.94
  6. Step 6: Final answer
    x = 608.90

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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.