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Finding the Fourth Proportional to 305.15, 420.95 and 231.35

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Solution

The fourth proportional to 305.15, 420.95 and 231.35 is: 319.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.15 : 420.95 = 231.35 : x
  2. Step 2: Convert to fraction form
    305.15/420.95 = 231.35/x
  3. Step 3: Cross multiply
    305.15x = 420.95 × 231.35
  4. Step 4: Simplify right side
    305.15x = 97,383.52
  5. Step 5: Solve for x
    x = 97,383.52/305.15
  6. Step 6: Final answer
    x = 319.13

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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.