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Finding the Fourth Proportional to 305.60, 421.44 and 256.40

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Solution

The fourth proportional to 305.60, 421.44 and 256.40 is: 353.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.60 : 421.44 = 256.40 : x
  2. Step 2: Convert to fraction form
    305.60/421.44 = 256.40/x
  3. Step 3: Cross multiply
    305.60x = 421.44 × 256.40
  4. Step 4: Simplify right side
    305.60x = 108,057.22
  5. Step 5: Solve for x
    x = 108,057.22/305.60
  6. Step 6: Final answer
    x = 353.59

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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.