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Finding the Fourth Proportional to 921.20, 1,271.24 and 528.30

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Solution

The fourth proportional to 921.20, 1,271.24 and 528.30 is: 729.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    921.20 : 1,271.24 = 528.30 : x
  2. Step 2: Convert to fraction form
    921.20/1,271.24 = 528.30/x
  3. Step 3: Cross multiply
    921.20x = 1,271.24 × 528.30
  4. Step 4: Simplify right side
    921.20x = 671,593.45
  5. Step 5: Solve for x
    x = 671,593.45/921.20
  6. Step 6: Final answer
    x = 729.05

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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.