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Finding the Fourth Proportional to 305.79, 421.65 and 281.49

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Solution

The fourth proportional to 305.79, 421.65 and 281.49 is: 388.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.79 : 421.65 = 281.49 : x
  2. Step 2: Convert to fraction form
    305.79/421.65 = 281.49/x
  3. Step 3: Cross multiply
    305.79x = 421.65 × 281.49
  4. Step 4: Simplify right side
    305.79x = 118,690.26
  5. Step 5: Solve for x
    x = 118,690.26/305.79
  6. Step 6: Final answer
    x = 388.14

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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.