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Finding the Fourth Proportional to 770.05, 1,155.39 and 405.16

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Solution

The fourth proportional to 770.05, 1,155.39 and 405.16 is: 607.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    770.05 : 1,155.39 = 405.16 : x
  2. Step 2: Convert to fraction form
    770.05/1,155.39 = 405.16/x
  3. Step 3: Cross multiply
    770.05x = 1,155.39 × 405.16
  4. Step 4: Simplify right side
    770.05x = 468,117.81
  5. Step 5: Solve for x
    x = 468,117.81/770.05
  6. Step 6: Final answer
    x = 607.91

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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.