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Finding the Fourth Proportional to 52.18, 78.54 and 39.40

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Solution

The fourth proportional to 52.18, 78.54 and 39.40 is: 59.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    52.18 : 78.54 = 39.40 : x
  2. Step 2: Convert to fraction form
    52.18/78.54 = 39.40/x
  3. Step 3: Cross multiply
    52.18x = 78.54 × 39.40
  4. Step 4: Simplify right side
    52.18x = 3,094.57
  5. Step 5: Solve for x
    x = 3,094.57/52.18
  6. Step 6: Final answer
    x = 59.31

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.