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Finding the Fourth Proportional to 52.20, 78.30 and 25.20

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Solution

The fourth proportional to 52.20, 78.30 and 25.20 is: 37.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    52.20 : 78.30 = 25.20 : x
  2. Step 2: Convert to fraction form
    52.20/78.30 = 25.20/x
  3. Step 3: Cross multiply
    52.20x = 78.30 × 25.20
  4. Step 4: Simplify right side
    52.20x = 1,973.16
  5. Step 5: Solve for x
    x = 1,973.16/52.20
  6. Step 6: Final answer
    x = 37.80

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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.