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Finding the Fourth Proportional to 210.40, 314.96 and 128.96

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Solution

The fourth proportional to 210.40, 314.96 and 128.96 is: 193.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.40 : 314.96 = 128.96 : x
  2. Step 2: Convert to fraction form
    210.40/314.96 = 128.96/x
  3. Step 3: Cross multiply
    210.40x = 314.96 × 128.96
  4. Step 4: Simplify right side
    210.40x = 40,617.24
  5. Step 5: Solve for x
    x = 40,617.24/210.40
  6. Step 6: Final answer
    x = 193.05

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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.