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Finding the Fourth Proportional to 65.86, 90.40 and 58.80

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Solution

The fourth proportional to 65.86, 90.40 and 58.80 is: 80.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    65.86 : 90.40 = 58.80 : x
  2. Step 2: Convert to fraction form
    65.86/90.40 = 58.80/x
  3. Step 3: Cross multiply
    65.86x = 90.40 × 58.80
  4. Step 4: Simplify right side
    65.86x = 5,315.52
  5. Step 5: Solve for x
    x = 5,315.52/65.86
  6. Step 6: Final answer
    x = 80.71

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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.