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Finding the Fourth Proportional to 285.76, 428.64 and 172.48

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Solution

The fourth proportional to 285.76, 428.64 and 172.48 is: 258.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.76 : 428.64 = 172.48 : x
  2. Step 2: Convert to fraction form
    285.76/428.64 = 172.48/x
  3. Step 3: Cross multiply
    285.76x = 428.64 × 172.48
  4. Step 4: Simplify right side
    285.76x = 73,931.83
  5. Step 5: Solve for x
    x = 73,931.83/285.76
  6. Step 6: Final answer
    x = 258.72

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.