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Finding the Fourth Proportional to 46.71, 64.29 and 39.78

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Solution

The fourth proportional to 46.71, 64.29 and 39.78 is: 54.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    46.71 : 64.29 = 39.78 : x
  2. Step 2: Convert to fraction form
    46.71/64.29 = 39.78/x
  3. Step 3: Cross multiply
    46.71x = 64.29 × 39.78
  4. Step 4: Simplify right side
    46.71x = 2,557.46
  5. Step 5: Solve for x
    x = 2,557.46/46.71
  6. Step 6: Final answer
    x = 54.75

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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.