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Finding the Fourth Proportional to 56.61, 78.03 and 39.15

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Solution

The fourth proportional to 56.61, 78.03 and 39.15 is: 53.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    56.61 : 78.03 = 39.15 : x
  2. Step 2: Convert to fraction form
    56.61/78.03 = 39.15/x
  3. Step 3: Cross multiply
    56.61x = 78.03 × 39.15
  4. Step 4: Simplify right side
    56.61x = 3,054.87
  5. Step 5: Solve for x
    x = 3,054.87/56.61
  6. Step 6: Final answer
    x = 53.96

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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.