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Finding the Fourth Proportional to 152.65, 210.65 and 87.15

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Solution

The fourth proportional to 152.65, 210.65 and 87.15 is: 120.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    152.65 : 210.65 = 87.15 : x
  2. Step 2: Convert to fraction form
    152.65/210.65 = 87.15/x
  3. Step 3: Cross multiply
    152.65x = 210.65 × 87.15
  4. Step 4: Simplify right side
    152.65x = 18,358.15
  5. Step 5: Solve for x
    x = 18,358.15/152.65
  6. Step 6: Final answer
    x = 120.26

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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.