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Finding the Fourth Proportional to 152.79, 210.82 and 86.40

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Solution

The fourth proportional to 152.79, 210.82 and 86.40 is: 119.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    152.79 : 210.82 = 86.40 : x
  2. Step 2: Convert to fraction form
    152.79/210.82 = 86.40/x
  3. Step 3: Cross multiply
    152.79x = 210.82 × 86.40
  4. Step 4: Simplify right side
    152.79x = 18,214.85
  5. Step 5: Solve for x
    x = 18,214.85/152.79
  6. Step 6: Final answer
    x = 119.21

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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.