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Finding the Fourth Proportional to 151.90, 209.64 and 89.70

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Solution

The fourth proportional to 151.90, 209.64 and 89.70 is: 123.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    151.90 : 209.64 = 89.70 : x
  2. Step 2: Convert to fraction form
    151.90/209.64 = 89.70/x
  3. Step 3: Cross multiply
    151.90x = 209.64 × 89.70
  4. Step 4: Simplify right side
    151.90x = 18,804.71
  5. Step 5: Solve for x
    x = 18,804.71/151.90
  6. Step 6: Final answer
    x = 123.80

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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.