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Finding the Fourth Proportional to 285.68, 393.90 and 220.16

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Solution

The fourth proportional to 285.68, 393.90 and 220.16 is: 303.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.68 : 393.90 = 220.16 : x
  2. Step 2: Convert to fraction form
    285.68/393.90 = 220.16/x
  3. Step 3: Cross multiply
    285.68x = 393.90 × 220.16
  4. Step 4: Simplify right side
    285.68x = 86,721.02
  5. Step 5: Solve for x
    x = 86,721.02/285.68
  6. Step 6: Final answer
    x = 303.56

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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.