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Finding the Fourth Proportional to 720.90, 994.80 and 406.15

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Solution

The fourth proportional to 720.90, 994.80 and 406.15 is: 560.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.90 : 994.80 = 406.15 : x
  2. Step 2: Convert to fraction form
    720.90/994.80 = 406.15/x
  3. Step 3: Cross multiply
    720.90x = 994.80 × 406.15
  4. Step 4: Simplify right side
    720.90x = 404,038.02
  5. Step 5: Solve for x
    x = 404,038.02/720.90
  6. Step 6: Final answer
    x = 560.46

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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.