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Finding the Fourth Proportional to 157.80, 217.70 and 99.64

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Solution

The fourth proportional to 157.80, 217.70 and 99.64 is: 137.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    157.80 : 217.70 = 99.64 : x
  2. Step 2: Convert to fraction form
    157.80/217.70 = 99.64/x
  3. Step 3: Cross multiply
    157.80x = 217.70 × 99.64
  4. Step 4: Simplify right side
    157.80x = 21,691.63
  5. Step 5: Solve for x
    x = 21,691.63/157.80
  6. Step 6: Final answer
    x = 137.46

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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.