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Finding the Fourth Proportional to 157.09, 216.79 and 90.71

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Solution

The fourth proportional to 157.09, 216.79 and 90.71 is: 125.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    157.09 : 216.79 = 90.71 : x
  2. Step 2: Convert to fraction form
    157.09/216.79 = 90.71/x
  3. Step 3: Cross multiply
    157.09x = 216.79 × 90.71
  4. Step 4: Simplify right side
    157.09x = 19,664.71
  5. Step 5: Solve for x
    x = 19,664.71/157.09
  6. Step 6: Final answer
    x = 125.18

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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.