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Finding the Fourth Proportional to 285.72, 394.32 and 161.40

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Solution

The fourth proportional to 285.72, 394.32 and 161.40 is: 222.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.72 : 394.32 = 161.40 : x
  2. Step 2: Convert to fraction form
    285.72/394.32 = 161.40/x
  3. Step 3: Cross multiply
    285.72x = 394.32 × 161.40
  4. Step 4: Simplify right side
    285.72x = 63,643.25
  5. Step 5: Solve for x
    x = 63,643.25/285.72
  6. Step 6: Final answer
    x = 222.75

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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.