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Finding the Fourth Proportional to 82.79, 123.58 and 71.45

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Solution

The fourth proportional to 82.79, 123.58 and 71.45 is: 106.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    82.79 : 123.58 = 71.45 : x
  2. Step 2: Convert to fraction form
    82.79/123.58 = 71.45/x
  3. Step 3: Cross multiply
    82.79x = 123.58 × 71.45
  4. Step 4: Simplify right side
    82.79x = 8,829.79
  5. Step 5: Solve for x
    x = 8,829.79/82.79
  6. Step 6: Final answer
    x = 106.65

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.