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Finding the Fourth Proportional to 152.90, 209.98 and 128.30

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Solution

The fourth proportional to 152.90, 209.98 and 128.30 is: 176.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    152.90 : 209.98 = 128.30 : x
  2. Step 2: Convert to fraction form
    152.90/209.98 = 128.30/x
  3. Step 3: Cross multiply
    152.90x = 209.98 × 128.30
  4. Step 4: Simplify right side
    152.90x = 26,939.70
  5. Step 5: Solve for x
    x = 26,939.70/152.90
  6. Step 6: Final answer
    x = 176.19

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.