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Finding the Fourth Proportional to 406.42, 560.28 and 289.78

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Solution

The fourth proportional to 406.42, 560.28 and 289.78 is: 399.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    406.42 : 560.28 = 289.78 : x
  2. Step 2: Convert to fraction form
    406.42/560.28 = 289.78/x
  3. Step 3: Cross multiply
    406.42x = 560.28 × 289.78
  4. Step 4: Simplify right side
    406.42x = 162,357.55
  5. Step 5: Solve for x
    x = 162,357.55/406.42
  6. Step 6: Final answer
    x = 399.48

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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.