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Finding the Fourth Proportional to 305.09, 420.35 and 275.54

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Solution

The fourth proportional to 305.09, 420.35 and 275.54 is: 379.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.09 : 420.35 = 275.54 : x
  2. Step 2: Convert to fraction form
    305.09/420.35 = 275.54/x
  3. Step 3: Cross multiply
    305.09x = 420.35 × 275.54
  4. Step 4: Simplify right side
    305.09x = 115,822.91
  5. Step 5: Solve for x
    x = 115,822.91/305.09
  6. Step 6: Final answer
    x = 379.64

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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.