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Finding the Fourth Proportional to 905.34, 1,352.76 and 720.78

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Solution

The fourth proportional to 905.34, 1,352.76 and 720.78 is: 1,076.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    905.34 : 1,352.76 = 720.78 : x
  2. Step 2: Convert to fraction form
    905.34/1,352.76 = 720.78/x
  3. Step 3: Cross multiply
    905.34x = 1,352.76 × 720.78
  4. Step 4: Simplify right side
    905.34x = 975,042.35
  5. Step 5: Solve for x
    x = 975,042.35/905.34
  6. Step 6: Final answer
    x = 1,076.99

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.