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Finding the Fourth Proportional to 212.08, 317.88 and 90.28

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Solution

The fourth proportional to 212.08, 317.88 and 90.28 is: 135.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.08 : 317.88 = 90.28 : x
  2. Step 2: Convert to fraction form
    212.08/317.88 = 90.28/x
  3. Step 3: Cross multiply
    212.08x = 317.88 × 90.28
  4. Step 4: Simplify right side
    212.08x = 28,698.21
  5. Step 5: Solve for x
    x = 28,698.21/212.08
  6. Step 6: Final answer
    x = 135.32

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.