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Finding the Fourth Proportional to 158.51, 218.78 and 103.15

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Solution

The fourth proportional to 158.51, 218.78 and 103.15 is: 142.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    158.51 : 218.78 = 103.15 : x
  2. Step 2: Convert to fraction form
    158.51/218.78 = 103.15/x
  3. Step 3: Cross multiply
    158.51x = 218.78 × 103.15
  4. Step 4: Simplify right side
    158.51x = 22,567.16
  5. Step 5: Solve for x
    x = 22,567.16/158.51
  6. Step 6: Final answer
    x = 142.37

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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.