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Finding the Fourth Proportional to 528.21, 728.88 and 307.11

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Solution

The fourth proportional to 528.21, 728.88 and 307.11 is: 423.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    528.21 : 728.88 = 307.11 : x
  2. Step 2: Convert to fraction form
    528.21/728.88 = 307.11/x
  3. Step 3: Cross multiply
    528.21x = 728.88 × 307.11
  4. Step 4: Simplify right side
    528.21x = 223,846.34
  5. Step 5: Solve for x
    x = 223,846.34/528.21
  6. Step 6: Final answer
    x = 423.78

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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.