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Finding the Fourth Proportional to 561.09, 774.29 and 312.39

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Solution

The fourth proportional to 561.09, 774.29 and 312.39 is: 431.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    561.09 : 774.29 = 312.39 : x
  2. Step 2: Convert to fraction form
    561.09/774.29 = 312.39/x
  3. Step 3: Cross multiply
    561.09x = 774.29 × 312.39
  4. Step 4: Simplify right side
    561.09x = 241,878.89
  5. Step 5: Solve for x
    x = 241,878.89/561.09
  6. Step 6: Final answer
    x = 431.09

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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.