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Finding the Fourth Proportional to 305.84, 421.64 and 253.20

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Solution

The fourth proportional to 305.84, 421.64 and 253.20 is: 349.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.84 : 421.64 = 253.20 : x
  2. Step 2: Convert to fraction form
    305.84/421.64 = 253.20/x
  3. Step 3: Cross multiply
    305.84x = 421.64 × 253.20
  4. Step 4: Simplify right side
    305.84x = 106,759.25
  5. Step 5: Solve for x
    x = 106,759.25/305.84
  6. Step 6: Final answer
    x = 349.07

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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.