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Finding the Fourth Proportional to 65.74, 90.80 and 57.55

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Solution

The fourth proportional to 65.74, 90.80 and 57.55 is: 79.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    65.74 : 90.80 = 57.55 : x
  2. Step 2: Convert to fraction form
    65.74/90.80 = 57.55/x
  3. Step 3: Cross multiply
    65.74x = 90.80 × 57.55
  4. Step 4: Simplify right side
    65.74x = 5,225.54
  5. Step 5: Solve for x
    x = 5,225.54/65.74
  6. Step 6: Final answer
    x = 79.49

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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.