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Finding the Fourth Proportional to 56.89, 78.47 and 39.38

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Solution

The fourth proportional to 56.89, 78.47 and 39.38 is: 54.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    56.89 : 78.47 = 39.38 : x
  2. Step 2: Convert to fraction form
    56.89/78.47 = 39.38/x
  3. Step 3: Cross multiply
    56.89x = 78.47 × 39.38
  4. Step 4: Simplify right side
    56.89x = 3,089.93
  5. Step 5: Solve for x
    x = 3,089.93/56.89
  6. Step 6: Final answer
    x = 54.32

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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.