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Finding the Fourth Proportional to 840.21, 1,257.89 and 565.35

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Solution

The fourth proportional to 840.21, 1,257.89 and 565.35 is: 846.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.21 : 1,257.89 = 565.35 : x
  2. Step 2: Convert to fraction form
    840.21/1,257.89 = 565.35/x
  3. Step 3: Cross multiply
    840.21x = 1,257.89 × 565.35
  4. Step 4: Simplify right side
    840.21x = 711,145.28
  5. Step 5: Solve for x
    x = 711,145.28/840.21
  6. Step 6: Final answer
    x = 846.39

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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.