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Finding the Fourth Proportional to 79.68, 109.50 and 62.40

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Solution

The fourth proportional to 79.68, 109.50 and 62.40 is: 85.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.68 : 109.50 = 62.40 : x
  2. Step 2: Convert to fraction form
    79.68/109.50 = 62.40/x
  3. Step 3: Cross multiply
    79.68x = 109.50 × 62.40
  4. Step 4: Simplify right side
    79.68x = 6,832.80
  5. Step 5: Solve for x
    x = 6,832.80/79.68
  6. Step 6: Final answer
    x = 85.75

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.