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Finding the Fourth Proportional to 210.40, 315.51 and 66.13

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Solution

The fourth proportional to 210.40, 315.51 and 66.13 is: 99.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.40 : 315.51 = 66.13 : x
  2. Step 2: Convert to fraction form
    210.40/315.51 = 66.13/x
  3. Step 3: Cross multiply
    210.40x = 315.51 × 66.13
  4. Step 4: Simplify right side
    210.40x = 20,864.68
  5. Step 5: Solve for x
    x = 20,864.68/210.40
  6. Step 6: Final answer
    x = 99.17

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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.