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Finding the Fourth Proportional to 86.30, 119.05 and 56.80

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Solution

The fourth proportional to 86.30, 119.05 and 56.80 is: 78.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.30 : 119.05 = 56.80 : x
  2. Step 2: Convert to fraction form
    86.30/119.05 = 56.80/x
  3. Step 3: Cross multiply
    86.30x = 119.05 × 56.80
  4. Step 4: Simplify right side
    86.30x = 6,762.05
  5. Step 5: Solve for x
    x = 6,762.05/86.30
  6. Step 6: Final answer
    x = 78.35

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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.