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Finding the Fourth Proportional to 78.95, 118.49 and 53.21

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Solution

The fourth proportional to 78.95, 118.49 and 53.21 is: 79.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.95 : 118.49 = 53.21 : x
  2. Step 2: Convert to fraction form
    78.95/118.49 = 53.21/x
  3. Step 3: Cross multiply
    78.95x = 118.49 × 53.21
  4. Step 4: Simplify right side
    78.95x = 6,304.59
  5. Step 5: Solve for x
    x = 6,304.59/78.95
  6. Step 6: Final answer
    x = 79.86

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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.