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Finding the Fourth Proportional to 52.10, 78.09 and 21.65

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Solution

The fourth proportional to 52.10, 78.09 and 21.65 is: 32.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    52.10 : 78.09 = 21.65 : x
  2. Step 2: Convert to fraction form
    52.10/78.09 = 21.65/x
  3. Step 3: Cross multiply
    52.10x = 78.09 × 21.65
  4. Step 4: Simplify right side
    52.10x = 1,690.65
  5. Step 5: Solve for x
    x = 1,690.65/52.10
  6. Step 6: Final answer
    x = 32.45

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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.