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Finding the Fourth Proportional to 210.90, 312.05 and 210.30

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Solution

The fourth proportional to 210.90, 312.05 and 210.30 is: 311.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.90 : 312.05 = 210.30 : x
  2. Step 2: Convert to fraction form
    210.90/312.05 = 210.30/x
  3. Step 3: Cross multiply
    210.90x = 312.05 × 210.30
  4. Step 4: Simplify right side
    210.90x = 65,623.47
  5. Step 5: Solve for x
    x = 65,623.47/210.90
  6. Step 6: Final answer
    x = 311.15

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Why These Related Problems?

These problems maintain the same ratio (1.48) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.