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Finding the Fourth Proportional to 114.80, 158.40 and 87.20

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Solution

The fourth proportional to 114.80, 158.40 and 87.20 is: 120.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    114.80 : 158.40 = 87.20 : x
  2. Step 2: Convert to fraction form
    114.80/158.40 = 87.20/x
  3. Step 3: Cross multiply
    114.80x = 158.40 × 87.20
  4. Step 4: Simplify right side
    114.80x = 13,812.48
  5. Step 5: Solve for x
    x = 13,812.48/114.80
  6. Step 6: Final answer
    x = 120.32

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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.