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Finding the Fourth Proportional to 305.49, 421.65 and 218.19

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Solution

The fourth proportional to 305.49, 421.65 and 218.19 is: 301.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.49 : 421.65 = 218.19 : x
  2. Step 2: Convert to fraction form
    305.49/421.65 = 218.19/x
  3. Step 3: Cross multiply
    305.49x = 421.65 × 218.19
  4. Step 4: Simplify right side
    305.49x = 91,999.81
  5. Step 5: Solve for x
    x = 91,999.81/305.49
  6. Step 6: Final answer
    x = 301.15

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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.